France and Spain helped the United States in their revolution since both of them had a hate for Britain. France had always been on bitter terms with Britain, especially after losing the Seven Years' War so they would do anything to provoke the King. The U.S. and Spain were closely associated with each other so Spain seeing the U.S. were enemies with Britain made a connection that they too also had the same opponent. In short, France and Spain both hated Britain just as the United States did.