challenge slave laws. Abolitionists were active on the lecture circuit in the North, and often featured escaped slaves in their presentations. Writer and orator Frederick Douglass became an important abolitionist leader after escaping from slavery. Harriet Beecher Stowe's novel Uncle Tom's Cabin (1852) was an international bestseller and aroused popular sentiment against slavery. It also provoked the publication of numerous anti-Tom novels by Southerners in the years before the American Civil War. Prohibiting the international trade Under the Constitution, Congress could not prohibit the import slave trade that was allowed in South Carolina until 1808. However, the third Congress regulated against it in the Slave Trade Act of 1794, which prohibited American shipbuilding and outfitting for the trade. Subsequent acts in 1800 and 1803 sought to discourage the trade by banning American investment in the trade, and American employment on ships in the trade, as well as prohibiting importation into states that had abolished slavery, which all states except South Carolina had by 1807. The final Act Prohibiting Importation of Slaves was adopted in 1807 and went into effect in 1808. However, illegal importation of African slaves (smuggling) was common. The Cuban slave trade between 1796 and 1807 was dominated by American slave ships. Despite the 1794 Act, Rhode Island slave ship owners found ways to continue supplying the slave-owning states. The overall U.S. slave-ship fleet in 1806 was estimated to be almost 75% the size of that of the British. After Great Britain and the United States outlawed the international slave trade in 1807, British slave trade suppression activities began in 1808 through diplomatic efforts and the formation of the Royal Navy's West Africa Squadron in 1809. The United States denied the Royal Navy the right to stop and search U.S. ships suspected as slave ships, so not only were American ships unhindered by British patrols, but slavers from other countries would fly the American flag to try to avoid being stopped. Co-operation between the United States and Britain was not possible during the War of 1812 or the period of poor relations in the following years. In 1820, the United States Navy sent , under the command of Captain Trenchard, to patrol the slave coasts of West Africa. Cyane seized four American slave ships in her first year on station. Trenchard developed a good level of co-operation with the Royal Navy. Four additional U.S. warships were sent to