On June 14, 1775, with war on the horizon, the Continental Congress resolved that "six companies of expert riflemen be immediately raised in Pennsylvania, two in Maryland, and two in Virginia." In 1777, this force of hardy frontiersmen provided the leadership and experiences necessary to form, under Dan Morgan, the organization George Washington called "The Corps of Rangers." According to British General John Burgoyne, Morgan's men were "...the most famous corps of the Continental Army, all of them crack shots."

Also active during the Revolutionary War were Thomas Knowlton's Connecticut Rangers. This force of less than 150 hand-picked men was used primarily for reconnaissance. Knowlton was killed leading his men in action at Harlem Heights.

Another famous Revolutionary War Ranger element was organized by Francis Marion, the "Swamp Fox." Marion's partisans, numbering up to several hundred, operated both with and independent of other elements of General Washington's army. Operating out of the Carolina swamps, they disrupted British communications and prevented the organization of loyalists to support the British cause, thus substantially contributing to the American victory.

During the War of 1812, Congress called for the Rangers to serve on the frontier. The December 28, 1813, Army Register lists officers for 12 companies of Rangers.