Kentucky v. Dennison

In the early 1840s, the main controversy over this question had concerned New York Governor William H. Seward. Seward had refused to send to Virginia three free African American men who had allegedly helped a slave to escape to New York. Virginia, a slave state, pointed out that each state had the right to decide what was legal and what was not. Since helping a slave to escape was illegal in Virginia, Seward ought to respect Virginia's laws and send the men back. Seward agreed that each state had the right to make its own laws, but argued that he was obligated only to enforce the laws of his own state. Since helping someone to escape from slavery was not a crime in his state, he had no obligation to enforce Virginia's laws. Moreover, in his opinion, the section of the Constitution that referred to returning fugitives from justice did not apply to this case. Seward also became involved in a similar controversy with the slave state of Georgia. Several Georgia governors had similar conflicts with governors of the free state of Maine.

When these kinds of conflicts occur between states, Congress often passes federal legislation to clarify the matter. In this case, however, Congress was torn between members from Southern states, who wanted to preserve slavery, and a growing number of abolitionists, who wished to abolish it. By the time of Kentucky v. Dennison, feelings were running strong on both sides.