Fugitive slaves in the United States

The phenomenon of slaves running away and seeking to gain freedom is as old as the institution of slavery itself. In the history of slavery in the United States, "fugitive slaves" (also known as runaway slaves) were slaves who left their master and traveled without authorization; generally they tried to reach states or territories where slavery was banned, including Canada. Most slave law tried to control slave travel by requiring them to carry official passes if traveling without a master.

Passage of the Fugitive Slave Act of 1850 increased penalties against fugitive slaves and people who aided them. Because of this, fugitive slaves tried to leave the United States altogether, traveling to Canada or Mexico. During the time slavery was legal in the United States, approximately 100,000 slaves escaped to freedom.

The United States Constitution included language to protect slavery, and the Fugitive Slave Act of 1793 implemented rules requiring citizens to aid in the return of escaped slaves to their owners. In practice, both citizens and governments of free states often supported the escape of fugitive slaves. Fugitive slaves early in U.S. were sought out just as they were through the Fugitive slave law years, but early efforts included only Wanted posters, flyers etc.

The Fugitive Slave Act of 1850 strengthened provisions for the recapture of slaves, and offered them no protection in the justice system. Bounty hunters and civilians could lawfully capture escaped slaves in the North, or any other place, using little more than an affidavit, and return them to the Slave master.

Many escaped slaves upon return were to face harsh punishments such as amputation of limbs, whippings, branding, and many other horrible acts.

Individuals who aided fugitive slaves were charged and punished under this law. In the case of Ableman v. Booth, Booth was charged with aiding Glover's escape in Wisconsin by preventing his capture by Federal Marshals. The Wisconsin Supreme Court ruled that the Fugitive Slave Act of 1850 was unconstitutional for requiring states to go against their own laws in protecting slavery. Ableman v. Booth was appealed by the federal government to the US Supreme Court, which upheld the constitutionality of the Act.

...
Wikipedia