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/

Beginning in the 16th century, European traders began to buy or capture people in the African continent to enslave and sell for profit. This trade began with Portugal and Spain, but it later expanded to include France, England, the Netherlands and other European countries. By the time the trading of enslaved people was finally put to an end in the 19th century, Europeans had abducted an estimated 12.5 million African people from their homelands, forced them onto ships, trafficked them to the Americas, and sold them on the auction block. Almost two million people died during transport; most of the rest were forced into labor camps, also called plantations. This extensive and gruesome human trafficking is commonly referred to as the transatlantic slave trade. The Portuguese began human trafficking in Africa by trading manufactured goods or money for Africans who had been captured during local wars. Later, some Europeans captured Africans themselves or paid other local Africans to do it for them. Europeans traded for or kidnapped Africans from many points on Africa’s coast, including Angola, Senegambia and Mozambique. Most of the people who were enslaved by the Europeans came from West and Central Africa.The most brutal segment of the route was the Middle Passage, which transported chained African people across the Atlantic Ocean as they were packed tightly below the decks of purpose-built ships in unsanitary conditions. This trip could last weeks or even months depending on conditions, and the trafficked people were subjected to abuse, dangerously high heat, inadequate food and water, and low-oxygen environments. Olaudah Equiano, a young boy who was forced into the Middle Passage after being captured in his home country of Nigeria, later described the foul conditions as “intolerably loathsome” and detailed how people died from sickness and lack of air. Approximately 1.8 million African people are thought to have died during the passage, accounting for about 15–25 percent of those who were taken from Africa.For many enslaved Africans trafficked across the Atlantic, the port at which their ship landed was not their final destination. Enslaved people were often transported by ship between two points in the Americas, particularly from Portuguese, Dutch and British colonies to Spanish ones. This was the intra-American slave trade. No matter where they landed, enslaved Africans faced brutal living conditions and high mortality rates. Moreover, any children born to enslaved persons were also born into slavery, usually with no hope of ever gaining freedom.This data set is the culmination of decades of archival research compiled by the SlaveVoyages Consortium. This data represents the trafficking of enslaved Africans from 1514 to 1866. All mapmakers must make choices when presenting data. This map layer represents individuals who experts can definitively place at a given location on one of at least 36,000 transatlantic and at least 10,000 intra-American human trafficking routes. However, this means the enslaved people for whom records cannot place their departure or arrival with certainty do not appear on this map (approximately 170,985 people). This map, therefore, is part of the story and not a complete accounting. You can learn more about the methodology of this data collection here.

These maps represent a modeled distribution of population based on the nominal censuses of the town of Curitiba and adjacent towns. Classification of data is normalized for each category to allow comparison between different periods of time.

These maps represent a modeled distribution of population based on the nominal censuses of the town of Curitiba and adjacent towns, providing a snapshot of the demographic situation in a specific year. Classification of data is normalized for each year to allow comparison between different categories of data for the same year.

The election of Abraham Lincoln in November of 1860 brought to a head the issue of slavery in the United States. In direct response to Lincoln's election as president, seven southern states seceded from the Union rather than continue to negotiate and compromise over the issue of slavery, which had been the norm for so many decades.This story map locates most of the major battles of the American Civil War. It was developed in partnership with the American Battlefield Trust.Many of the descriptions for individual sites include links to excellent battlefield maps, articles and in-depth analysis from the American Battlefield Trust. The Trust is America's largest non-profit organization devoted to the preservation of our nation's endangered battlefields. The Trust also promotes educational programs and heritage tourism initiatives to inform the public of the war's history and the fundamental conflicts that sparked it. See additional story maps at esri.com/arcgisstorymaps.

In the past four centuries, the population of the United States has grown from a recorded 350 people around the Jamestown colony of Virginia in 1610, to an estimated 331 million people in 2020. The pre-colonization populations of the indigenous peoples of the Americas have proven difficult for historians to estimate, as their numbers decreased rapidly following the introduction of European diseases (namely smallpox, plague and influenza). Native Americans were also omitted from most censuses conducted before the twentieth century, therefore the actual population of what we now know as the United States would have been much higher than the official census data from before 1800, but it is unclear by how much. Population growth in the colonies throughout the eighteenth century has primarily been attributed to migration from the British Isles and the Transatlantic slave trade; however it is also difficult to assert the ethnic-makeup of the population in these years as accurate migration records were not kept until after the 1820s, at which point the importation of slaves had also been illegalized. Nineteenth century In the year 1800, it is estimated that the population across the present-day United States was around six million people, with the population in the 16 admitted states numbering at 5.3 million. Migration to the United States began to happen on a large scale in the mid-nineteenth century, with the first major waves coming from Ireland, Britain and Germany. In some aspects, this wave of mass migration balanced out the demographic impacts of the American Civil War, which was the deadliest war in U.S. history with approximately 620 thousand fatalities between 1861 and 1865. The civil war also resulted in the emancipation of around four million slaves across the south; many of whose ancestors would take part in the Great Northern Migration in the early 1900s, which saw around six million black Americans migrate away from the south in one of the largest demographic shifts in U.S. history. By the end of the nineteenth century, improvements in transport technology and increasing economic opportunities saw migration to the United States increase further, particularly from southern and Eastern Europe, and in the first decade of the 1900s the number of migrants to the U.S. exceeded one million people in some years. Twentieth and twenty-first century The U.S. population has grown steadily throughout the past 120 years, reaching one hundred million in the 1910s, two hundred million in the 1960s, and three hundred million in 2007. In the past century, the U.S. established itself as a global superpower, with the world's largest economy (by nominal GDP) and most powerful military. Involvement in foreign wars has resulted in over 620,000 further U.S. fatalities since the Civil War, and migration fell drastically during the World Wars and Great Depression; however the population continuously grew in these years as the total fertility rate remained above two births per woman, and life expectancy increased (except during the Spanish Flu pandemic of 1918).

Since the Second World War, Latin America has replaced Europe as the most common point of origin for migrants, with Hispanic populations growing rapidly across the south and border states. Because of this, the proportion of non-Hispanic whites, which has been the most dominant ethnicity in the U.S. since records began, has dropped more rapidly in recent decades. Ethnic minorities also have a much higher birth rate than non-Hispanic whites, further contributing to this decline, and the share of non-Hispanic whites is expected to fall below fifty percent of the U.S. population by the mid-2000s. In 2020, the United States has the third-largest population in the world (after China and India), and the population is expected to reach four hundred million in the 2050s.

As the United States acquired land and new states formed, the balance of power between the free and slave states needed to be addressed. The activity uses a web-based map and is tied to the C3 Framework.

Learning outcomes:

Students will be able to explain how the Missouri Compromise, the Compromise of 1850, and the Kansas-Nebraska Act led to conflict and not to peace.

Find more US History GeoInquiries here or explore all GeoInquiries at https://www.esri.com/geoinquiries

The map title is Northwest Territories. Tactile map scale. 1.5 centimetres = 150 kilometres North arrow pointing to the top of the page. Borders of the Northwest Territories, shown as solid lines. The Great Bear Lake, Great Slave Lake, shown with a wavy symbol to indicate water. A filled star and the city name Yellowknife to show the location of Yellowknife. Text labels for Banks Island, Victoria Island, Great Bear Lake, Great Slave Lake and the Mackenzie River. The word lake is abbreviated as L, the work River is abbreviated as R and the word Island is abbreviated as I. The abbreviation "YT" to indicate the Yukon Territory. The abbreviation "BC" to indicate the province of British Columbia. The abbreviation "AB" to indicate the province of Alberta. The abbreviation "SK" to indicate the province of Saskatchewan. The abbreviation "NU" to indicate the Territory of Nunavut. Tactile maps are designed with Braille, large text, and raised features for visually impaired and low vision users. The Tactile Maps of Canada collection includes: (a) Maps for Education: tactile maps showing the general geography of Canada, including the Tactile Atlas of Canada (maps of the provinces and territories showing political boundaries, lakes, rivers and major cities), and the Thematic Tactile Atlas of Canada (maps showing climatic regions, relief, forest types, physiographic regions, rock types, soil types, and vegetation). (b) Maps for Mobility: to help visually impaired persons navigate spaces and routes in major cities by providing information about streets, buildings and other features of a travel route in the downtown area of a city. (c) Maps for Transportation and Tourism: to assist visually impaired persons in planning travel to new destinations in Canada, showing how to get to a city, and streets in the downtown area.