At the Constitutional Convention in 1787, delegates fiercely debated the issue of slavery. They ultimately agreed that the United States would potentially cease importation of slaves in 1808. An act of Congress passed in 1800 made it illegal for Americans to engage in the slave trade between nations, and gave U.S. authorities the right to seize slave ships which were caught transporting slaves and confiscate their cargo. Then the "Act Prohibiting the Importation of Slaves" took effect in 1808.