In 1819 Congress passed yet another act that dramatically changed the regulation of the trade. First, it authorized the president to send "armed vessels of the United States, to be employed to cruise on any of the coasts of the United States ... or the coast of Africa" to interdict slave traders. This was the beginning of what became known as the African Squadron, which patrolled the waters off the coast of Africa in an attempt to stop the slave trade at its source.
The law also provided that the slaves be returned to Africa, rather than being sold in the United States. This provision was directly tied to the creation of the African Squadron. The act authorized the president to appoint agents to receive rescued Africans and return them to the continent of their birth. The United States would use Liberia as a destination for Africans taken off intercepted ships. American ships could not seize slavers off the coast of Africa and immediately return the people on board to their point of origin. The law provided an economic incentive for sailors on these ships: a $25 bounty, to be shared by the crew of the interdicting vessel, for every individual rescued from traders. The act also provided a bounty of $50 per person to any informant whose information led to the recovery of illegally introduced Africans.
This act changed the direction of the suppression of the trade. The focus was now in part on the injustice of enslaving someone who deserved to be free. In part, the law now implicitly condemned American slavery itself. If it was wrong - unlawful - to enslave an African after 1819, why, someone might ask, was it not wrong to enslave an African before 1808? And if the original enslavement was morally wrong, then what was the basis of holding the descendants of that person in slavery? The act also took the United States out of the business of marketing slaves. Before 1819 confiscated slaves were sold under the laws of the states where they ended up. Naval crews and informants were in part compensated from the sale of these people. Now the taxpayers compensated naval crews and informants through bounties and the Africans went home. This was a dramatic change in American policy. For the first time in the nation's history, the United States was willing to spend money to help Africans regain their liberty.