Were it not for French assistance, it is unlikely that the American Revolutionary War would’ve succeeded — or at least done so as quickly and relatively easily as it did.
Along with Great Britain, France was the greatest military and political power in the world at that time. Aside from significant diplomatic and financial support, France supplied the Patriots with boots, uniforms, supplies, and the most advanced weaponry at the time (including hundreds of cannons and thousands of rifles that outperformed the British ones). Indeed, 90% of our gunpowder was of French origin, and the lack of that alone would’ve made rebellion near-impossible. France provided a navy (as we had none); trained, advised, and even led our troops (hence, in part, the prevalence of French terms in military parlance), and opened up additional battle fronts throughout the world, which helped to spread out and weaken the Crown’s forces.
A total of 300,000 French troops were involved in the conflict, one of the largest armed forces at the time (and one that presumably outnumbered the British). Many of them fought alongside the Patriots; in fact, the decisive Siege of Yorktown — which ultimately ended the war — was won by a combined Franco-American force, involving as many French troops as American ones. Granted, France did all this more for strategic gain against a perennial rival than out of any sympathy to our cause (though some French did support us for ideological reasons). But the facts don’t lie, and our liberation of France in World War II can, in a sense, be seen as returning the favor.
Note that Spain also played an important role as well, after the French convinced them to join in. Unfortunately, Spanish contributions are even less well-known than French ones, and require further scholarship and research.
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