The war being over, 2LT Morris returned home and began a civilian life deeply involved in community activities attending dances and playing second base for the Staunton Kiwanis Baseball Club among other things.
Promoted to 1LT, Morris was assigned on 10 Aug 1922 as the Training and Plans Officer for the 116th Infantry Regiment commanded by COL Hierome Opie. In October of that same year he joined the Staunton Acca Temple Shriners and in November became the secretary-treasurer of the Staunton Section of the Army Association.
In April 1923 he became engaged to Virginia Worthington, daughter of a prominent Staunton businessman. The couple was married on 19 Jun 1923. He was promoted to CPT in October 1923. Morris and Virginia had and lost an infant daughter on 24 Aug 1925. He joined the American Legion and the Trinity Episcopal Church Mens' Club. He also started the Staunton Novelty Company making pennants, banners and flags as well as a variety of other products. Another daughter was born on 23 May 1927. In August 1928 CPT Warner was made Adjutant of the 116th Infantry. As he expanded his participation in the community he was also starting a business and was first noted as President of the Staunton Novelty Company in 1931 the same year in which he was made President of the Trinity Episcopal Church Mens' Club. Morris and Virginia had a son join the family on 4 Oct 1932.
The next decade began with the world drifting towards war and in August 1940 Morris was promoted to LTC and assumed command of 3rd Battalion 116th Infantry. His rank was federally recognized in January 1941 and he was made executive officer of 116th Infantry. He began a 3 month Battalion Commanders and Staff Officers course at Infantry School, Fort Benning, Georgia in February 1941 and resigned from Staunton Electoral Board due to his military commitment. The regiment was federalized and sent to Fort George Meade, Maryland while he was at Fort Benning. On his return to the regiment in April 1941 he assumed duties as instructor in charge of 29th Division junior officers school. As the regiment continued to train for deployment COL E. W. Opie was promoted and reassigned and LTC Warner assumed command of the 116th Infantry Regiment in September 1942 and commanded the unit as it arrived in England and began training there. He was succeeded by COL Canham in March 1943 and promoted to COL in August 1943 while commanding the 156th Infantry Regiment at the assault training center in England. He would lead that regiment onto the continent and in its mission of containing bypassed German units before making a final thrust at the end of the war.
COL Warner returned to the U.S. in October 1945 and went into inactive status in November. Resuming his civilian life he was named to the Staunton Zoning Board of Appeals in May 1947. Morris also became active in the Staunton District of Boy Scouts of America and would be active in scouting administration for many years. In December 1950 he was elected President of Thornrose Cemetery Company, Inc. He participated in the 1954 ground-breaking for the Staunton's Thomas D. Howie National Guard Armory.
COL Warner was made a Virginia State Brigadier General and was referred to by that rank. He suffered from Parkinson's in his later years and died of a heart attack on 17 Jan 1982. He was interred in Thornrose Cemetery in Staunton, Virginia.