The particular case that forced the U.S. Congress's hand in 1793 centered around John Davis. Pennsylvania's governor, Thomas Mifflin, sought the extradition of three Virginians accused of kidnapping Davis and taking him to Virginia. Virginia's governor, Beverly Randolph, refused the extradition request on the grounds that Davis was a fugitive slave subject to rendition. Mifflin objected, claiming that Davis was free and should be protected. The 1793 Fugitive Slave Law was written in response to this interstate struggle. This law marked the first of several federal attempts to balance the rights of personal liberty and personal property when one state's recognition of liberty directly impinged on another state's recognition of property rights in slaves.
Although slaves' legal status as property disqualified them from claiming constitutional rights, the Fugitive Slave Law of 1793 denied these rights to freed slaves as well. Escaped slaves were not allowed jury trials, and it was not uncommon for runaways to be refused permission to present proof of their freedom in court.
The law gave teeth to the provisions of the U.S. Constitution that protected slavery. It made it a federal crime to assist an escaping slave, and established the legal mechanism by which escaped slaves could be seized (even in "free" states), brought before a magistrate, and returned to their masters. The Act made every escaped slave a fugitive-for-life, liable to recapture at any time anywhere within the territory of the United States, along with any children subsequently born of enslaved mothers. A whole industry of slave-catching developed in response to the Act, and even free blacks were sometimes unlawfully seized by slave-catchers and sold into slavery. The Act had a chilling effect on the lives of the one-fifth of the American population that was of African descent, and the Underground Railroad developed in response to it. Congress passed the Fugitive Slave Act overwhelmingly in February 1793, and President George Washington signed it into law on February 12, 1793.