Between 1779 and 1782, Spain pressed the British in such disparate places as Gibraltar, the Caribbean, and Central America, and even threatened to invade Britain’s home islands, thus tying up dozens of British warships and numerous regiments of British regulars. Luckily for the United States, two key regions important to America became Spanish priorities as well – British held Florida and the Mississippi River Valley. Almost singlehandedly, the Spanish removed the British from West Florida, which forced England to also relinquish East Florida as part of the terms to end the war.

Despite cultural differences, Spain and Americans living west of the Appalachians became natural allies in the fight against England. The welfare of both was tied to the Mississippi River and the port of New Orleans, and both wanted the British out of the region. Over the course of the war, Spain provided loans that allowed the United States to purchase over 200 cannons, 30,000 muskets and bayonets, half a million musket balls, and 150 tons of gun powder, most of it going to support George Rogers Clark’s western army. Importantly, these supplies kept America’s fragile western war effort alive when our own Congress was helpless to send Clark any munitions.

Even before America’s declaration of independence, Spain began to secretly supply the colonists with war materials. Soon after France and the United States signed its Treaty of Alliance, Spain declared war on England to support her French cousins, thus indirectly becoming America’s ally. Spain stretched British war-fighting capacity beyond the breaking point, turning a regional war into a costly conflict between the world’s two greatest colonial empires.