William King of Delaware was appointed 2nd Lieutenant in the 5th Regiment of Infantry in 1808; made 1st Lieutenant 1810; served as Regimental Adjutant from March 1811 to July 1812.
He was promoted to Captain in the 15th Infantry in July 1812; served on the Niagara frontier and commanded a detachment of 150 men at the Battle of Frenchman's Creek 28 November 1812.
He was promoted to Major in March of 1813 and Colonel in July of that year. In 1813 he also served as the Adjutant General of the Right Wing of the 9th Military District commanded by General Wade Hampton.
He was appointed Colonel of the new 3rd Regiment of Rifles in February of 1814; transferred to the new 4th Infantry Regiment in March 1815, honorably discharged June 1821 and died in 1826.
Colonel King's career is typical of that of the pre-war infantry officers who fought on the northern theater of the War of 1812, particularly in the Ninth Military District, and made the cut into the smaller post-war army.