The beginning of the United States military lies in civilian frontiersmen, armed for hunting and basic survival in the wilderness. These were organized into local militias for small military operations, mostly against Native American tribes but also to resist possible raids by the small military forces of neighboring European colonies. They relied on the support of the British regular army and navy for any serious military operation.

In the early years of the British colonization of North America, military action in the colonies that would become United States were the result of conflicts with Native Americans, such as in the Pequot War of 1637, King Philip's War in 1675, and the Yamasee War in 1715. Slave uprisings such as the Stono Rebellion in 1739, and inter-colonial conflicts, such as the Pennamite Wars and the activities of the Green Mountain Boys, were also a part of the colonial military experience.

Beginning in 1689, the colonies also frequently became involved in a series of wars between Great Britain and France for control of North America, the most important of which were Queen Anne's War, in which the British annexed French Acadia, and the final French and Indian War (1754–1763). This final war was to give thousands of colonists, including George Washington, military experience which they put to use during the American Revolution.