Kentucky v. Dennison
At the time, the decision was seen as a victory for Southern states' right to demand that Northern states support the institution of slavery. The decision supported the ability of a governor to refuse to extradite a fugitive from justice to another state until it was reversed by Puerto Rico v. Branstad (1987).
The years before the Civil War were full of legal battles between the slave states and the free states. In 1793, Congress had passed a law providing for the return of fugitive slaves. This law drew on Article IV, Section 2 of the Constitution, which read:
A person charged in any State with treason, felony, or other crime, who shall flee from justice, and be found in another State, shall on demand of the executive authority of the State from which he fled, be delivered up, to be removed to the State having jurisdiction of the crime.
In other words, if a person committed a crime in one state and ran away to another, the second state was supposed to return the person to the first state, where he or she could stand trial. Since running away from slavery was considered a crime in the slave states, a slave who ran away, or a person who helped a slave run away, was supposed to be returned to stand trial.
Of course, abolitionists--people who opposed slavery--objected to this use of the law. Since abolitionists believed that slavery was wrong, they wanted to help slaves escape to freedom. They wanted slaves to be able to remain in those parts of the United States where they could be free.
Law Library - American Law and Legal InformationNotable Trials and Court Cases - 1833 to 1882Kentucky v. Dennison - Significance, Who Decides?, A Slave Girl And The Man Who Helped Her, On The Eve Of The Civil War