How did the American colonies win the war?
In explaining the outcome of the war, scholars have pointed out that the British never contrived an overall general strategy for winning it. Also, even if the war could have been terminated by British power in the early stages, the generals during that period, notably Howe, declined to make a prompt, vigorous, intelligent application of that power. They acted, to be sure, within the conventions of their age, but in choosing to take minimal risks (for example, Carleton at Ticonderoga and Howe at Brooklyn Heights and later in New Jersey and Pennsylvania) they lost the opportunity to deal potentially mortal blows to the rebellion. There was also a grave lack of understanding and cooperation at crucial moments (as with Burgoyne and Howe in 1777). Finally, the British counted too strongly on loyalist support they did not receive.
But British mistakes alone could not account for the success of the United States. Feeble as their war effort occasionally became, the Americans were able generally to take advantage of their enemies’ mistakes. The Continental Army, moreover, was by no means an inept force even before Steuben’s reforms. The militias, while usually unreliable, could perform admirably under leaders who understood them, such as Arnold, Greene, and Morgan, and often reinforced the Continentals in crises. Furthermore, Washington, a rock in adversity, learned slowly but reasonably well the art of generalship. The supplies and funds furnished by France from 1776 to 1778 were invaluable, while French military and naval support after 1778 was essential. The outcome, therefore, resulted from a combination of British blunders, American efforts, and French assistance.