One of the many factors that led to the American Civil War was the debate over whether states had the right to secede from the Union as defined in the Constitution. The South argued that slaves in their possession were legal property and should remain so if they were brought to Northern states; further, that any state had the right to secede based on the concept that the Constitution was a free compact, or agreement, between sovereign states. Under that interpretation, if a state decided that it no longer wished to support the Union, it should be able to secede. The North, led by Abraham Lincoln, argued that the Constitution was a legally-binding contract that could not simply be broken at will; it was incumbent on each state to comply with the Federal Government according to law, and secession was prohibited by legal agreements including language in the Fourth Amendment, which assigned state roles and rights as related to the Federal Government. The South persisted in their secession movement, claiming that the Constitution was not legally-binding to free states, and that they were under no moral or ethical requirement to accede to a Federal Government with which they disagreed.