Democritus was the one who came up with the concept and the name ( atomos in Greek means "no-cut").\n. \nDemocritus was mostly lucky, not prescient; the scientific method in ancient Greece largely consisted of coming up with as many wacky ideas as they possibly could, under the theory that eventually someone's wacky idea was bound to be right.
There were actually several times in history that american indians became allies with english colonists and fight other american indians, but the most significant was during the French and Indian war.