John Henry Eaton was born in 1790 in Halifax County, North Carolina. He attended the University of North Carolina from 1803 to 1804 but never received a degree. Eaton decided to study law and ultimately became a lawyer in Tennessee after service in the War of 1812 as a private. He then became a representative in the Tennessee state legislature and served until 1816. In 1817, he published a book on the life of Andrew Jackson which attracted the favorable attention of his subject. A friendship evolved between Jackson and Eaton, and in 1818 Jackson convinced the Tennessee legislature to fill a United States Senate vacancy with Eaton, even though Eaton did not meet the thirty-year age requirement. Eaton served in the Senate from 1818 to 1829, winning reelection twice. He left the Senate in 1829 when President Andrew Jackson appointed him secretary of war, a post he held until 1831. A close associate of Jackson's, Eaton was ostracized by many in the President's cabinet due to his marriage to a woman of low social position. Eaton resigned his post in 1831; soon thereafter, President Jackson demanded the resignations of almost his entire cabinet. Three years later, after two failed attempts to return to the United States Senate, President Jackson named Eaton the territorial governor of Florida. Within two years, Eaton had left that position to become, again at Jackson's request, the United States minister to Spain. He lost the post and returned to the United States in 1840 when he chose not to support the candidacy of the new President, Martin Van Buren. John Henry Eaton died in 1856.

For further reading: Latner, Richard B. "The Eaton Affair Reconsidered." Tennessee Historial Quarterly 36 (1977): 330-51.