Four specific instances where Religion was a key factor in US history

1.) The Witch Trials, where women were accused and executed for witchcraft in the late 1600's, was based off of pure religious belief that witches were women that practiced dark magic for Satan himself.

2.) The original US colonies were based on the fact that the colonists felt persecuted in England for the different religious views that they held from the English.

3.) Slaves that were brought to the early years of the US were often forced to practice forms of religion that their master viewed righteous, which was usually a form of Christianity.

4.) Native Americans in the past, had been persecuted and hunted down for their different beliefs, ironically enough. Even if the Colonists left England for religious freedom, that didn't stop them from chasing down the Natives for their widely different beliefs after time.