In January 1800, Izard became aide-de-camp to Army commander Alexander Hamilton. A few months later he was invited by William Loughton Smith, Minister Plenipotentiary to Portugal, to serve as his secretary, a position he accepted. He left Portugal the next year and returned to the United States. He officially resigned his army commission in June 1803.
In March 1812, Izard was appointed as Colonel of the newly organised 2d Artillery Regiment. He was promoted to Brigadier-General a year later, and served as Wade Hampton's second in command until his resignation, when Izard succeeded him. Promoted to Major-General in January 1814, he was in charge of the Northern Army protecting Lake Champlain, until ordered to reinforce the Army of Niagara. He was discharged in June 1815.[3]
Governor of Arkansas Territory (1825–1828)
Izard was appointed Governor of Arkansas Territory in March 1825, and served until his death in 1828.[4] He died of complications of gout in Little Rock. Originally buried near the Peabody School there, Izard's remains were moved to Mount Holly Cemetery in 1843.[5]