Article IV, Section 2, Clause 3, the so-called Fugitive Slave Clause, provides, “No person held to Service or Labour in one state, under the Laws thereof, escaping into another, shall, in Consequence of any Law or Regulation therein, be discharged from such Service or Labour, but shall be delivered up on Claim of the Party to whom such Service or Labour may be due.” This provision is one of the bundle of provisions inserted into the Constitution to protect the interests of the slaveholding states as a condition for their entering the new system. Although the clause itself does not specify who has the power or responsibility to “deliver up” escaped slaves, Congress very early passed a Fugitive Slave Act (1793). This law provided that an owner or “his agents or attorney” could apply to a federal judge in any state to which a slave had fled, and upon minimal proof of ownership be given a certificate to return the escapee to the state of servitude. The law also set penalties against those found guilty of aiding fugitive slaves in their efforts to escape. The law was controversial on two grounds at least: the question arose as to whether Congress possessed authority to enforce the Fugitive Slave Clause, and objections were raised about the lack of protection afforded to alleged escaped slaves. Many northern states responded with laws attempting to establish protection for free blacks and, even, to frustrate the reclaiming of fugitives. These actions in turn led to increased demands from the slaveholding states for better enforcement of the Fugitive Slave Clause. Part of the Compromise of 1850 was a new Fugitive Slave Act, providing special federal commissioners and other devices to make it easier for fugitive slaves to be recovered, and striking forcefully against the efforts by states or private individuals to protect free blacks or frustrate the recapture of fugitives. The law proved to be a source of great friction in the years leading up to the war.
Don E. Fehrenbacher, The Slave Holding Republic (New York: Oxford University Press, 2001).