Under the Treaty of Alliance (1778), in return for support in the American Revolutionary War, the United States agreed to defend French interests in the Caribbean. As the treaty had no termination date, this included protecting them from Great Britain and the Dutch Republic during the 1792–1797 War of the First Coalition. Despite popular enthusiasm for the French Revolution, there was little support for this in Congress; neutrality allowed Northern shipowners to earn huge profits evading the British blockade, and Southern plantation-owners feared the example set by France's abolition of slavery in 1794.