Charles Lee brought European and North American military experience to the Revolution. A British officer during the Seven Years' War, he served in the campaigns against New France and later served in European armies. He settled in America in 1773 and bought a Virginia estate. When Congress organized the Continental Army in 1775, it commissioned him a major general, ranking behind Washington and Artemas Ward.

Lee helped direct the siege of Boston and prepared defenses at Newport and New York before taking charge in the Southern Department. The successful defense of Charleston in 1776 raised his reputation, although William Moultrie's fort and troops carried the main fighting. Returning north, Lee became critical of Washington's leadership. British cavalry captured him at a New Jersey lodging in December 1776. While a prisoner he submitted military advice to British commanders, a matter unknown to the Americans when he was exchanged in 1778.

At Monmouth on June 28, 1778, Lee commanded the American advance guard. A confused attack and retreat brought a confrontation with Washington, followed by Lee's demand to answer the criticism. A court-martial convicted him of disobedience, misconduct in retreat, and disrespect, suspending him for a year. He continued attacking Washington and Congress and was dismissed from the army in 1780. He spent his remaining years outside military command and died in Philadelphia in 1782. His conduct in captivity and at Monmouth remains debated.