After the war, Ellis entered politics and was elected to the Louisiana State Senate from 1866-1870, then served in Congress from 1875-1885.

[1] During the Civil War he joined the Confederate States Army and was commissioned a first lieutenant.

Ellis was promoted to captain in the Sixteenth Regiment, Louisiana Infantry, and served two years until he was captured at the Battle of Missionary Ridge, Tennessee, about November 25, 1863.

He served as chairman of the Committee on Mississippi Levees (Forty-fourth Congress) but declined to be a candidate for renomination in 1884.

He died there April 25, 1889 and was interred in the Ellis family cemetery at "Ingleside," near Amite, Tangipahoa Parish, Louisiana.