George Washington was given the difficult task of organizing and leading a militia against one of the most powerful armies in the world at that time. If it wasn't for his amazing leadership abilities, the American militia would have been completely annihilated within the first year of warfare, and this has been proven.
The geological location of America is 4,900 miles away from Europe. The Britain's needed to ship everything from weapons, guns, and men to America, which sometimes took almost half a year. Time was of essence, and because travel was not permitted during the winter, the time gap was very narrow. Ultimately, the inconsistence of shipment of men and supplies was definitely the downfall of the Red Coats.
The colonists were tough. Even after many losses and deaths (20% of the American population died during the war), the fortitude and perseverance if the colonists was the main reason why the reason why the American revolution was won. Keep in mind that without men, there is no war. Considering the circumstances and lifestyle of the time, the colonists could have easily given up.
Cheers to our forefathers!