How were the colonist able to defeat the british during the American revolution war of 1775-1781?

France beat Britain, the colonists were supplied with most of their firearms from france, France sent over thousands of soldiers. The French navy trapped Cornwallis. Prussia was annoyed at England for breaking its alliance and created a neutrality league where a number of English allies did not join the war effort. France had Spain and the Dutch helping them, so England was fighting for it survival. France bankrupted their own government doing this, England did not have enough resources to protect the 13 colonies and was more interested in preserving other parts of the empire.