Spain played an important role in the independence of the United States, as part of its conflict with Britain. Spain declared war on Britain as an ally of France, itself an ally of the American colonies. Most notably, Spanish forces attacked British positions in the south and captured West Florida from Britain in the siege of Pensacola. This secured the southern route for supplies and closed off the possibility of any British offensive through the western frontier of the United States via the Mississippi River. Spain also provided money, supplies, and munitions to the American forces.

Beginning in 1776, it jointly funded Roderigue Hortalez and Company, a trading company that provided critical military supplies. Spain provided financing for the final siege of Yorktown in 1781 with a collection of gold and silver in Havana, then Spanish Cuba.^[50] Spain was allied with France through the Bourbon Family Compact and the Revolution was an opportunity to confront their common enemy, Great Britain. As the newly appointed Chief Minister of King Charles III of Spain, the Count of Floridablanca wrote in March 1777, "the fate of the colonies interests us very much, and we shall do for them everything that circumstances permit".^[51]

Spanish aid was supplied to the new nation through four main routes: from French ports with the funding of Rodrigue Hortalez and Company, through the port of New Orleans and up the Mississippi River, from the warehouses in Havana, and from Bilbao, through the Gardoqui family trading company.