What other nations helped the Patriot cause during the American Revolution?

By the time the Revolution rolled around, Britain was the dominant colonial power in the world. This also meant that they were the target for other large colonial powers. Spain (who had been the dominant power in the 1500s) despised English growth in the Caribbean, and France had fought wars on and off with Britain for close to 100 years. Meanwhile, Dutch traders were bitter about their replacement by the British as the key traders in the world.

Even before the war started, each of these three countries had begun supplying the Patriots with arms and ammunition. It was difficult to send arms through British ports, and, following 1763, Britain controlled the entire Eastern seaboard north of Florida. France, Spain, and the Netherlands all owned islands in the Caribbean however, and Spain owned Florida. Arms would be sent through the islands, up through Florida, and into the hands of colonists.

After the outbreak of war in 1775, the countries refrained from publicly proclaiming support for the new United States. For the most part, it was thought that Britain would quickly crush the rebellion or make amends. The other countries were content in secretly prolonging the war by supplying weapons. After the Battle of Saratoga in 1777, however, the French came to believe the Patriots could pose a significant threat with support, and soon after they gave public recognition to the United States as a country, and declared war on Britain.

Spain and the Netherlands followed suit over the next two years, though France was the only country to supply significant military aid outside of arms and ammunition. The French navy immediately distracted the British with fighting closer to home. Eventually the French set up a blockade that enabled the siege and eventually surrender at Yorktown.