Smyth served in the United States Army from 1808 to 1813.
Commissioned as a
colonel in 1808, he served as
Inspector General to William Eustis, the acting War Secretary. Shortly after the outbreak of the
War of 1812, Smyth was promoted to
brigadier general on July 6, 1812. During the
Battle of Queenston Heights he refused to support his commander, General
Stephen Van Rensselaer, a
militia commander with no experience. After Van Rensselaer's disgrace, Smyth was given command and proved himself equally inept. His plan to invade Canada started with the
Battle of Frenchman's Creek but was then abandoned because of problems due to poor organization. After the failed attack on Canada, Smyth was insulted by Brigadier General
Peter B. Porter, who accused Smyth of cowardice. Smyth challenged Porter to a duel, but both men went unscathed. The historian John R. Elting wrote of the duel, stating, "Unfortunately, both missed." In the wake of his failure, Smyth's name was removed from the U.S. Army rolls. ==Postwar career==