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.

The issue of race and slavery was arguably the largest cause of the American Civil War, with the southern states seceding from the Union as the practice of slavery became increasingly threatened. From the graph we can see that roughly 16.5 percent of the entire US population at this time was black, and the vast majority of these were slaves. In 1860 there were almost 27 million white people, four and a half million black people, and less than one hundred thousand non-black or white people (mostly of Native/Latin American or East-Asian origin).

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.

Analysis of ‘Waffles and divorce rates’ provided by Analyst-2 (analyst-2.ai), based on source dataset retrieved from https://www.kaggle.com/tylerbonnell/waffles on 13 February 2022.

--- Dataset description provided by original source is as follows ---

Context

This dataset comes from the book Statistical Rethinking: A Bayesian Course with Examples in R and Stan

Content

Location : State name

Loc : State abbreviation

Population : 2010 population in millions

MedianAgeMarriage: 2005-2010 median age at marriage

Marriage : 2009 marriage rate per 1000 adults

Marriage.SE : Standard error of rate

Divorce : 2009 divorce rate per 1000 adults

Divorce.SE : Standard error of rate

WaffleHouses : Number of diners

South : 1 indicates Southern State

Slaves1860 : Number of slaves in 1860 census

Population1860 : Population from 1860 census

PropSlaves1860 : Proportion of total population that were slaves in 1860

Acknowledgements

All credit should go to Richard McElreath: https://xcelab.net/rm/statistical-rethinking/

--- Original source retains full ownership of the source dataset ---

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.