The U.S. Coast Survey map calculated the number of slaves in each county in the United States in 1860. Library of Congress In September of 1861, the U.S. Coast Survey published a large map ...

In 1860, a United States census counted nearly four million enslaved people living in the country. The Civil War was fought between abolitionists and the pro-slavery Confederacy, until the ...

From 1820 to 2013, 79 million people obtained lawful permanent resident status in the United States. The interactive map above visualizes all of them based on their prior country of residence.