Fugitive Slave Act of 1793 in the context of "Personal liberty laws"

In the United States before 1865, a free state was a state in which slavery and the internal or domestic slave trade were prohibited, while a slave state was one in which they were legal. Between 1812 and 1850, it was considered by the slave states to be politically imperative that the number of free states not exceed the number of slave states, so new states were admitted in slave–free pairs. There were, nonetheless, some slaves in most free states up to the 1840 census, and the Fugitive Slave Clause of the U.S. Constitution, as implemented by the Fugitive Slave Act of 1793 and the Fugitive Slave Act of 1850, provided that a slave did not become free by entering a free state and must be returned to their owner. Enforcement of these laws became one of the controversies that arose between slave and free states.

By the 18th century, slavery was legal throughout the Thirteen Colonies, but at the time of the American Revolution, rebel colonies started to abolish the practice. Pennsylvania abolished slavery in 1780, and about half the states had abolished slavery by the end of the Revolutionary War or in the first decades of the new country's existence, although, depending on the jurisdiction, this did not mean that all slaves became immediately free due to gradual abolition. Vermont — having declared its independence from Britain in 1777 and thus not being one of the Thirteen Colonies — banned slavery in the same year, before being admitted as a state in 1791.

Fugitive slaves or runaway slaves were historical terms used in the 18th and 19th centuries to describe individuals who fled the institution of slavery in the United States. Modern historical scholarship often prefers the terms self-emancipated people or freedom seekers to acknowledge the active role these individuals took in claiming their own liberty.

The history of self-emancipation is linked to two federal laws that established the right of retrieval: the Fugitive Slave Act of 1793 and the Fugitive Slave Act of 1850. The legal status of a person escaping slavery was initially addressed in the United States Constitution's Fugitive Slave Clause (Article IV, Section 2, Clause 3), which mandated the return of such individuals to the party claiming ownership. This legal framework, in tension with resistance efforts like the Underground Railroad and Northern "personal liberty laws," intensified the sectional conflict between slaveholding states and free states, contributing significantly to the causes of the American Civil War.

The fugitive slave laws were laws passed by the United States Congress in 1793 and 1850 to provide for the return of slaves who escaped from one state into another state or territory. The idea of the fugitive slave law was derived from the Fugitive Slave Clause which is in the United States Constitution (Article IV, Section 2, Paragraph 3). It was thought that forcing states to return fugitive slaves to their masters violated states' rights due to state sovereignty, and that seizing state property should not be left up to the states. The Fugitive Slave Clause states that fugitive slaves "shall be delivered up on Claim of the Party to whom such Service or Labour may be due", which abridged state rights because apprehending runaway slaves was a form of retrieving private property. The Compromise of 1850 entailed a series of laws that allowed slavery in the new territories and forced officials in free states to give a hearing to slave-owners without a jury.