Note: Explore this map with the activity The Underground Railroad.This map shows which states and territories in 1850 permitted the enslavement of people, and which did not. Slavery had been practiced in North America since well before the United States was founded in 1776, and by 1850 it was a key part of the agricultural economy of the southern states. Large cotton plantations operated on the labor of enslaved people, particularly Black Africans. Meanwhile, the northern United States had a more industrial economy, and by 1850 had mostly prohibited slavery for economic, political, and moral reasons. Though these states were considered “free” states, in many cases this meant that slavery wasn’t widespread. Even in states and territories where slavery was technically illegal, there were many loopholes that kept people enslaved and restricted free Black people.

In the years before the American Civil War, which began in 1861, the question of whether new states would allow slavery caused a lot of disagreement and tension between the North and South. The United States was carefully balanced to have as many "slave" states as "free" states, giving both sides an equal number of senators. The South was worried that if more free states were added, this balance would be upset, and the North would be able to pass legislation banning slavery in the United States. The North didn't want slavery to spread to new areas, both for moral reasons and because they didn’t think it was fair that enslaved people couldn’t vote but counted as part of the population when assigning congressional delegates. They argued that this gave the South an unfair advantage when voting for new laws. To try to keep the peace, a series of compromises, such as the Missouri Compromise of 1820 were proposed to determine what states and territories would or would not permit slavery.

Another issue that caused tension between abolitionists in the North and slave owners in the South was the ongoing trade of enslaved people. The United States government had banned foreign slave trade in 1800, but this did nothing to free the people who were already enslaved in the United States. States in the upper South, such as Virginia, now profited from selling enslaved people to new states in the Deep South.

To escape enslavement, some enslaved people used an informal network of routes, places, and people known as the Underground Railroad to travel in secret to the Northern United States and into Canada, where slavery was illegal. The Underground Railroad was not a literal underground railroad, but because escaping from slavery and helping enslaved people escape was illegal, the network operated in secret. The “conductors” were the people leading enslaved people to freedom and the “station masters,” those who hid enslaved people on the way north. According to some estimates, between 1810 and 1850, the Underground Railroad helped to guide 100,000 enslaved people to freedom.

This map was made through the process of digitization, or tracing historical maps using modern geographic information system (GIS) software. These maps don’t always line up perfectly with modern boundaries, for many reasons. Over time, natural landmarks, such as rivers, can shift their paths, and human landmarks, such as buildings and roads, can be abandoned and demolished. There are also differences in the accuracy of hand-drawn maps compared to computer-drawn maps.

The original maps are published in Harper’s Atlas of American History, and are available through the Library of Congress:

Slavery and Slave Trade 1830-1850

Routes of the Underground Railroad 1830-1865

Fox, Dixon Ryan. Harper's atlas of American history, selected from "The American nation series," with map studies, by Dixon Ryan Fox. [New York, London, Harper & Brothers, 1920] Pdf. https://www.loc.gov/item/32005827/

There were almost 700 thousand slaves in the US in 1790, which equated to approximately 18 percent of the total population, or roughly one in every six people. By 1860, the final census taken before the American Civil War, there were four million slaves in the South, compared with less than 0.5 million free African Americans in all of the US. Of the 4.4 million African Americans in the US before the war, almost four million of these people were held as slaves; meaning that for all African Americans living in the US in 1860, there was an 89 percent* chance that they lived in slavery. A brief history Trans-Atlantic slavery began in the early sixteenth century, when the Portuguese and Spanish forcefully brought captured African slaves to the New World, in order to work for them. The British Empire introduced slavery to North America on a large scale, and the economy of the British colonies there depended on slave labor, particularly regarding cotton, sugar and tobacco output. In the seventeenth and eighteenth century the number of slaves being brought to the Americas increased exponentially, and at the time of American independence it was legal in all thirteen colonies. Although slavery became increasingly prohibited in the north, the number of slaves remained high during this time as they were simply relocated or sold from the north to the south. It is also important to remember that the children of slaves were also viewed as property, and (apart from some very rare cases) were born into a life of slavery. Abolition and the American Civil War In the years that followed independence, the Northern States began gradually prohibiting slavery, and it was officially abolished there by 1805, and the importation of slave labor was prohibited nationwide from 1808 (although both still existed in practice after this). Business owners in the Southern States however depended on slave labor in order to meet the demand of their rapidly expanding industries, and the issue of slavery continued to polarize American society in the decades to come. This culminated in the election of President Abraham Lincoln in 1860, who promised to prohibit slavery in the newly acquired territories to the west, leading to the American Civil War from 1861 to 1865. Although the Confederacy (south) were victorious in much of the early stages of the war, the strength in numbers of the northern states (including many free, black men), eventually resulted in a victory for the Union (north), and the nationwide abolishment of slavery with the Thirteenth Amendment in 1865. Legacy In total, an estimated twelve to thirteen million Africans were transported to the Americas as slaves, and this does not include the high number who did not survive the journey (which was as high as 23 percent in some years). In the 150 years since the abolishment of slavery in the US, the African-American community have continuously campaigned for equal rights and opportunities that were not afforded to them along with freedom. The most prominent themes have been the Civil Rights Movement, voter suppression, mass incarceration and the relationship between the police and the African-American community has taken the spotlight in recent years.

This statistic shows the number of black men and women in the US from 1820 until 1880. Slavery was legal in the Southern States of the US until 1865, when the Thirteenth Amendment was added to the US Constitution after the American Civil War. Until that time all of the slaves included in this statistic were registered as living in the South, whereas the majority of the free, black men and women lived in the Northern States. From the data we can see that, while the slave experience was very different for men and women, there was relatively little difference between their numbers in each respective category. While female slaves were more likely to serve in domestic roles, they were also more likely to be working in the lowest and unskilled jobs on plantations, whereas men were given more skilled and physically demanding roles. As slavery was abolished in 1870, all black people from this point were considered free in the census data. It is also worth noticing that in these years the difference in the number of men and women increased, most likely as a result of all the black male soldiers who fell fighting in the American Civil War.

This dataset classifies information on approximately 1,700 escravos de ganho, or rental slaves, in Rio de Janeiro, Brazil between 1850 and 1880. Culled from a sample of announcements published in the city’s main business newspaper, the Jornal do Commercio (est. 1827), the dataset systematically records the sex and occupations of enslaved peoples advertised for hire. When available, it also includes information on age, race, rental rates, location of the owner, and additional observations on the occupational training, character, and capabilities of the available enslaved person. The dataset includes a sample of advertisements published every ten years beginning in 1850. The four years of the sample correspond to some of the major events leading to final emancipation in 1888, including the closing of the transatlantic slave trade (1850) and the Law of the Free Womb (1871). The dataset includes links to the original full-text classified advertisement, found in digitized copy in the Brazilian National Library’s Hemeroteca Digital.

Screenshot of Slave census database William H. Marriott - 1850

According to records regarding the White House (i.e. census data and purchase or rental contracts), at least 201 slaves were known to have been hired from their owner to help build the White House and Capitol Building between 1792 and 1800. The source details that many slaves involved in this feat were undocumented, therefore the number of slaves who actually took part was likely much higher. Similarly, records also show that there were a number of slaves recorded as living or working on the White House grounds until 1850, during the tenure of ten of the first twelve U.S. presidents. It is important to note, however, that these figures apply only to the slaves who moved with the president to the White House (or were hired from their respective owner), and this data is not reflective of the number of slaves owned by U.S. presidents throughout their lifetimes.

Of these first twelve presidents, John Adams and William Henry Harrison were the only to not have slaves living with them in the White House, although Harrison was an advocate of slavery and was a slave owner during his lifetime. Adams' son, John Quincy Adams, also held a strong anti-slavery stance throughout his political career, however, when John Quincy's sister-in-law and brother-in-law died in 1813 and 1815 respectively, their four children went to stay in the White House and brought with them a small number of slaves.

This replication package contains code, data, and documentation to replicate the analyses in "Wealth, Slave Ownership, and Fighting for the Confederacy: An Empirical Study of the American Civil War." Abstract: How did personal wealth and slaveownership affect the likelihood southerners fought for the Confederate Army in the American Civil War? On the one hand, wealthy southerners had incentives to free-ride on poorer southerners and avoid fighting; on the other hand, wealthy southerners were disproportionately slaveowners, and thus had more at stake in the outcome of the war. We assemble a dataset on roughly 3.9 million free citizens in the Confederacy, and show that slaveowners were more likely to fight than non-slaveowners. We then exploit a randomized land lottery held in 1832 in Georgia. Households of lottery winners owned more slaves in 1850 and were more likely to have sons who fought in the Confederate Army. We conclude that slaveownership, in contrast to some other kinds of wealth, compelled southerners to fight despite free-rider incentives because it raised their stakes in the war's outcome.

This study recorded information on deaths that occurred in 1850 in seven states of the southern United States: Georgia, Kentucky, Louisiana, North Carolina, South Carolina, Tennessee, and Texas. The data were obtained from the manuscript mortality schedules of the 1850 United States Census. Variables identify the state and county in which each death occurred, and provide information on the age, sex, race, legal status (free or slave), place of birth, and occupation of the deceased. The month and cause of death as well as the number of days of illness before death are also documented.

Between 1501 and 1866, it is estimated that over 12.5 million people were forced onto ships in Africa, and transported to the Americas as slaves. Furthermore, it is estimated that only 10.7 million of these slaves disembarked on the other side of the Atlantic, meaning that roughly 1.8 million did not survive the journey. The transatlantic slave trade was a part of the triangular trade route between Europe, Africa and the Americas, during the sixteenth and nineteenth centuries. Generally speaking, this route saw European merchants bring manufactured products to Africa to trade for slaves, then transport the slaves to the Americas to harvest raw materials, before taking these materials back to Europe where they would then be consumed or used in manufacturing. Slavery was an integral part in funding the expansion of Europe's colonial empires, which shaped the modern and highly globalized world in which we live today.

The Middle Passage As with trade, the slave journey was also broken into three parts; the First Passage was the stage where slaves were captured and transported to African ports, the Middle Passage was the journey across the Atlantic, while the Final Passage was where the slaves were transported to their place of work. The death toll in the First Passage is thought to be the highest of the three stages, as millions were killed or fatally wounded as they were captured, however a lack of written data and historical evidence has made this number difficult to estimate. In contrast, shipping records from the time give a much more accurate picture of the Middle Passage's death toll, and this data suggest that roughly 14.5 percent of slaves did not survive the journey. The reason for this was the harsh and cramped conditions on board; slave ships were designed in such a way that they could fit the maximum number of slaves on board in order to maximize profits. These conditions then facilitated the spread of diseases, such as smallpox and dysentery, while malnutrition and thirst created further problems. Generally, slavers aimed to keep slaves as healthy (therefore; profitable) as possible, although there are countless examples of mistreatment and punishment of slaves by their captors, and several cases where slaves were exterminated by the crew as provisions ran low.

Rise and fall of the transatlantic slave trade

The European arrival in the Americas also saw the introduction of virgin soil epidemics (new diseases being introduced to biologically defenseless populations) which decimated the indigenous populations. The abundance of natural resources, but lack of available labor led to the rise of the transatlantic slave trade. Until the mid-1600s, Portuguese traders had a near-monopoly on this trade, supplying slaves to the newly expanding Spanish and Portuguese empires in South America. As other European powers began to expand their empires in the Caribbean and North America, the slave trade grew dramatically, and during the eighteenth century, the number of slaves being brought to the New World increased from an annual average of thirty thousand in the 1690s to 87 thousand in the 1790s. The transatlantic slave trade reached its peak between the 1750 and 1850, and an average of 74 thousand slaves were brought to the Americas each year between these dates. The largest decline came as the slave trade was disrupted during the American War of Independence (1775-1783), although the trade became weakened as the abolitionist movement gained momentum in Europe and the Americas around the turn of the century. The most significant impacts came as the slave trade was abolished in Britain and the U.S. in 1807 and Brazil in 1831, and Britain then used its position as the global superpower to impose abolition on other nations and used the Royal Navy to enforce these measures. While most nations abolished the slave trade in the early 1800s, it would take decades before the actual practice of slavery would be abolished; today, slavery is illegal in almost every country, however modern slavery in the forms of forced labor, human trafficking and sexual exploitation continues to be prevalent across the globe.

McLysaght's "Irish Families" cross referenced with the U.S. Slave Schedules (1850) and the Slave Compensation Records (1834). I believe that my data, while cursory, is suggestive of the level of slave-ownership among those of Irish descent. Hopefully this ‘first pass’ review will lead to more in-depth research that will tease out the complexities of these family histories.

The “Rio de Janeiro Wet-Nursing Database” (RJWND) comprises all advertisements for wet nurses for the year of 1850 in Rio de Janeiro, Brazil, extracted from the city’s main commercial newspaper, Jornal do Commercio. “Mercenary” wet nursing, what contemporaries called the practice of paying for other women to breastfeed their children, was a thriving market throughout the nineteenth century. Enslaved women comprised most wet nurses, with freed women of color and white immigrant women also working in the trade. More rarely, white Brazilian women whose newborns had died advertised their milk. We can draw several conclusions from this data. Most importantly, RJWND demonstrates the ubiquity of wet nursing in urban Brazil. All women participated in this activity, whether as elite mothers not breastfeeding their own children, or as free, freed, freed African, and enslaved women breastfeeding other women’s children. It also sheds light on how enslavers valued wet nurses both for their reproductive labors (wet nursing) and their productive outputs (cleaning, cooking).

This dataset is about books. It has 1 row and is filtered where the book is Slavery, Memory and Religion in Southeastern Ghana, c.1850-present. It features 7 columns including author, publication date, language, and book publisher.

This dataset documents the records of mainly Black people incarcerated in the Tennessee State Penitentiary in the period directly before, during, and after the Civil War, from 1850-1870. It includes a staggering amount of formerly enslaved Civil War soldiers and veterans who had enlisted in the segregated regiments of the United States Military, the U.S.C.T. This demographic information of over 1,400 inmates incarcerated in an occupied border state allows us to examine trends, patterns, and relationships that speak to the historic ties between the US military and the TN State Penitentiary, and more broadly, the role of enslavement’s legacies in the development of punitive federal systems. Further analysis of this dataset reveals the genesis of many modern trends in incarceration and law. The dataset of this article and its historiographical implications will be of interest to scholars who study the regional dynamics of antebellum and post-Civil War prison systems, convict leasing and the development of the modern carceral state, Black resistance in the forms of fugitivity and participation in the Civil War, and pre-war era incarceration of free Black men and women and non-Black people convicted of crimes related to enslavement.

At the beginning of the 19th century, the U.S. labor force was approximately 1.9 million people, with slaves making up over half a million (28 percent) of this number. The share of slaves then increased to almost one third of the overall workforce in the next decade, but dropped to roughly one fifth by 1860; the year before the American Civil War. While the total number of slaves grew by several hundred thousand in each decade, their share of the U.S. labor force decreased due to the high levels of European migration to the U.S. throughout the 19th century. This wave of mass migration was an influential factor in slavery's eventual abolition, as Europeans met the labor demands that had previously been fulfilled by slaves, and those fleeing persecution and oppression in Europe were often sympathetic to the plight of slaves. Nonetheless, the majority of European migrants arrived in the industrialized, northern states, most of which had already abolished slavery in the 18th century, and slave labor was concentrated in the agricultural south at this time; this divide would prove fundamental in the outbreak of the American Civil War.

This dataset documents the manumissions of 5,133 enslaved African and Brazilian-born persons that were recorded in Livros de Notas (LNs) written in Salvador, Bahia, Brazil, between 1831 and 1840; additional decades are forthcoming. The volumes are deposited in the public archives of the state of Bahia (Arquivo Púbico do Estado da Bahia, or APEB) in Salvador. The Livros de Notas were created by officials called tabeliães (notaries) who copied legal documents of different kinds into large bound volumes they maintained for the preservation and safe keeping of important records. When completed, our dataset of manumissions will be one of the largest and most comprehensive of any for Brazil, containing information about many thousands of men, women, and children freed in the province of Bahia between 1801 and 1850. Although the dataset was not conceived for the purpose, even the subset published here shows that it will be a rich source of aggregated as well as micro-historical data about manumission. The variables in the dataset permit analysis of the roles of gender; origin, nação, and color; and, to a lesser extent, age and occupation in manumission.

Between 1775 and 1841, the population of Cuba grew to almost six times its size, from approximately 170 thousand people to over one million. During these years, Cuba was a Spanish colony, where slavery remained legal. In 1841, slaves counted for almost 45% of the total population.

Sugar industry A large reason for this growth was the emergence of the sugar industry, as production was relocated from areas of the Caribbean where slavery was abolished (most notably Haiti in 1804 and Jamaica in 1834). Although Cuba had been a Spanish colony for almost three centuries before these figures begin, it was economically isolated and trade with other nations was restricted; following a brief occupation by the British in the 1860s, international trade became encouraged, and a slave-based plantation complex emerged. By the middle of the 19th century, Cuba had established itself as the largest producer of sugar in the world (a position that it held until the mid-20th century), with the U.S. as it's primary consumer.

Gender differences From the figures for 1827 and 1841, the disparities between the male and female populations become apparent. Males migrated to the Americas at a much higher rate than females, while African males were also captured and enslaved at a higher rate than females during the Atlantic slave trade. This is reflected in the slave and white populations, although the difference within the slave population is much greater. Conversely, among free people of color, the female population population is actually higher than the number of males; this was due to a number of reasons, such as higher rates of manumission among females (the ratio of female to male manumissions was estimated to be around 3:2 in the Caribbean in the 19th century) and higher life expectancy.

This data collection contains information about the population of each county, town, and city of the United States in 1850 and 1860. Specific variables include tabulations of white, black, and slave males and females, and aggregate population for each town. Foreign-born population, total population of each county, and centroid latitudes and longitudes of each county and state were also compiled. (Source: downloaded from ICPSR 7/13/10)

Please Note: This dataset is part of the historical CISER Data Archive Collection and is also available at ICPSR -- https://doi.org/10.3886/ICPSR09424.v2. We highly recommend using the ICPSR version as they made this dataset available in multiple data formats.

Of the first eighteen presidents of the United States, twelve owned slaves throughout their lifetime, and eight of these were slave owners while occupying the office of president. Of the U.S.' first twelve presidents, the only two never to own slaves were John Adams, and his son John Quincy Adams; the first of which famously said that the American Revolution would not be complete until all slaves were freed. George Washington, leader of the revolution and the first President of the United States, owned many slaves throughout his lifetime, with 123* at the time of his death. Historians believe that Washington's treatment of his slaves was typical of slaveowners in Virginia at the time, however he did develop moral issues with the institution of slavery following the revolution. Washington never publicly expressed his growing opposition to slavery, although he did stipulate in his will that all his slaves were to be freed following the death of his wife, and he made financial provisions for their care that lasted until the 1830s.

Jefferson controversies

In recent years, the legacy of Thomas Jefferson has come under the most scrutiny in relation to this matter; the man who penned the words "all men are created equal" is estimated to have owned at least 600 slaves throughout the course of his lifetime. Before becoming president, Jefferson argued for restrictions on the slave trade, and against its expansion into new US territories; however he avoided the subject during his presidency as the topic grew in divisiveness and he believed that emancipation would not be achieved during his lifetime. It is also widely accepted that Jefferson had an affair and likely fathered children with one of his slaves, Sally Hemmings, who is also believed to be the half-sister of Jefferson's first wife. DNA tests conducted in the 1990s confirmed a genetic link between the descendants of the Jefferson and Hemings families, but could not confirm whether the link was Jefferson himself or a relative; most historians however, believe that Jefferson fathered at least one of Sally Hemings' children, and possibly six or eight of them (all of whom were kept as Jefferson's slaves).

Other Presidents

Of the other presidents who appear on this list, all are regarded differently for their attitudes towards slavery, and their impact on the eventual abolition of slavery and the emancipation of slaves. Madison and Monroe grew up in slave-owning families, and owned a number of slaves while serving in the White House; interestingly, Monrovia, the capital city of Liberia (the country was founded by the American Colonization Society as an African settlement for freed slaves), was named in Monroe's honor as he was a prominent advocate of the ACS. Andrew Jackson, who earned a large portion of his private wealth via the slave trade, introduced legislation that protected slave owners and slavery in the southern states; he owned around 200 slaves at the time of his death, and many more throughout his lifetime. John Tyler publicly decried slavery and claimed that it was evil, although he owned slaves as he said this and his political actions in his later life actually supported the institution of slavery (Tyler is notably the only U.S. president whose death was not mourned officially as he was involved in the government of the Confederacy at the time).

Perhaps the most surprising names on this list are Andrew Johnson and Ulysses S Grant, the vice president and leader of the United States Army during the latter stages of the American Civil War. Neither men owned slaves while in office, although Johnson, the man who oversaw the ratification of the Thirteenth Amendment, is reported to have owned eight slaves before entering the world of politics. Ulysses S. Grant, who managed his wife's family's farm in the 1850s, inherited one slave in 1854 who he then freed two years later. Grant's armies would eventually free countless slaves in the 1860s, as he led the Union to victory against the Confederacy and brought an end to slavery in the United States.

Brazil conducted its first nationwide census in 1872, just 16 years before slavery's official abolition in 1888. Modern estimates place Brazil's total population in 1872 at approximately 10.3 million; the exclusion of non-white infants and indigenous populations from the census is likely the cause of this deficit. The 1872 census showed that non-whites made up the majority of Brazil's population at this time, at roughly 5.75 million, compared to the white population of 3.79 million. Of these 5.75 million, over 4.2 million were free, compared to 1.5 million living in slavery; this gives a ratio of almost three free non-whites for every one slave. To compare, in the United States in 1860, there were at least eight slaves for every one free person of color in the years leading up to slavery's nationwide abolition.

Sumner, Charles, 1811-1874, compiler. Volume I. Fugitive slaves : scrapbook of clippings, 1850-1860., 1850-1860.