In my Opinion as support by facts
The first one is that they were well armed and organized. The Colonist was well regulated in their militias and were able to repel invasions and tyrannical moves by the British Empire.
They had great leadership, patriots, and philosophy. George Washington, John Stark, John Pual Jones, Ethan Allen, Pual Revere just to name a few of American Leaders, let alone the countless amount of brave men who stood against the most powerful nation in the world at that time.
These men followed the philosophy to the likings of John Locke, as well as the Sons of Liberty.
They had French Support. The French allied with the Americans and gave full military support. So much so that large portraits of the French King and Queen were put inside Congress Hall as a sign of respect and gratitude for the French.
