"But the Main Purpose of Militias—North and South—During This Period Was to Suppress Slave Rebellions"

"Throughout the 17th century, almost all the English colonies along the Eastern Seaboard passed legislation prohibiting women and slaves from owning guns and forbidding the sale of guns to native peoples. By the 18th century, gun ownership had become a defining feature of white masculinity in the English colonies and guns played an integral role in Colonial men's public displays of that masculinity.
"The public training exercises Colonial men participated in as part of their militia service were central to such displays and offered opportunities for them to participate in competitions to demonstrate their martial prowess. In many cases, guns were not only central to these demonstrations but were the prize for victory. The commander of the militia in Henrico County, Va., William Byrd, noted in his diary that he made a practice of awarding pistols to the men who won the competitions that took place on militia days. Such guns thus acted as material manifestations of a Colonial man's physical domination of his peers, augmenting his reputation in terms of property ownership and bodily prowess."

Nathan Wuertenberg at The Washington Post explains the origins of American gun culture.

And Thom Hartmann in a 2013 Truthout article explains how slave patrols ended up in the Second Amendment.