Henry Lee IV represented Westmoreland County in the Virginia House of Delegates from 1810 to 1813, then served as a major and staff officer in the War of 1812. His subsequent prospects depended partly on managing family property at Stratford Hall. In 1817 he married Anne McCarty, but his affair with her younger sister Betsy, whose property he controlled as guardian, led to litigation over his misuse of her inheritance and income.

A chancery judgment in 1822 helped force the sale of Stratford and damaged Lee's political and social standing. He turned increasingly to writing. His Campaign of 1781 in the Carolinas, published in 1824, defended the military reputation of his father, Henry “Light-Horse Harry” Lee, and challenged interpretations favorable to Nathanael Greene. Lee also became a supporter and publicist for Andrew Jackson, contributing to Jackson's presidential campaign and helping prepare his first inaugural address.

Jackson appointed him consul at Algiers in 1829 during a congressional recess, but the Senate rejected the nomination in 1830. Lee later moved to Paris, where he continued literary work while separated from Virginia's political life. His books included Observations on the Writings of Thomas Jefferson in 1832 and a work on Napoleon in 1834; he also attempted a biography of Jackson that remained incomplete. He died in Paris in 1837. His financial and family scandal sharply limited his opportunities for public office.