Later, Plummer commanded the 5th Division of Pope's army at New Madrid[1] and the Island Number Ten campaign. He subsequently commanded a brigade of Stanley's division at Corinth and died in camp at Corinth on August 9, 1862 (exactly one year after Wilson's Creek) from lingering effects of his wounds and prolonged exposure in the field.[1]
Plummer was also friendly with his wife's brother, Temple Clark, who also served in the Mexican–American War and was a Union Army officer in the Civil War. He invited Temple Clark to join his staff in the Army of the Mississippi in the months before his death.[4]
Plummer and his wife had two children, Satterlee Clark Plummer and Lydia Lee Plummer. Satterlee Clark Plummer graduated from the United States Military Academy in 1865 and was a career U.S. Army officer like his father. He died of pneumonia in 1881 at the home of his mother, in Washington, D.C., and was posthumously promoted to captain.[5] Lieutenant Plummer also wrote correspondence for newspapers under the pen name "Sleeping Friar".[6]
^Some controversy exists regarding Plummer's year of birth. See the notes and gravestone photos in the External links section. Warner, 1964, p. 374 gives this date but says that he seems to have taken a few years off his age so as not to endanger an appointment to the military academy which he sought for at least two years.