Britain banned its slave trade in 1807. Between 1807 and 1860, the RN anti-slavery patrols seized approximately 1,600 ships and 150,000 Africans who were then transported to the British colony of Sierra Leone, where they served as 'apprentices' in the colonial economy. During much of this time France was under blockade by the RN. Somehow I doubt Lafitte or the French were able to smuggle 2 1/2 million slaves from Jamaica, a British colony, to the US between 1807 and the end of 1814. If Lafitte was smuggling slaves from Jamaica it would be more likely he was acting in collusion with British slave owners in the colony.

According to Wikipedia: "In April 1818, the United States passed a law prohibiting the import of slaves into any port in the United States. The law left several loopholes, however. It essentially gave permission to any ship to capture a slave ship, regardless of the country from which it originated. Furthermore, any newly imported slaves who were turned over to the customs office would be sold within the United States, with half the profits of the sale going to the people who turned them in. Lafitte worked with several smugglers, including Jim Bowie, to profit from the poorly written law. Lafitte's men would target ships that carried slaves. Smugglers would purchase the slaves for a discounted price, march them to Louisiana, and turn them in to customs officials. A representative of the smuggler would purchase the slaves at the ensuing auction, and the smuggler would be given half of the purchase price. The smuggler was then the lawful owner of the slaves and could transport them to sell in other parts of the United States."