[2] Following his return to Tennessee, Morris was named rector of St. Mary's Cathedral in Nashville and private secretary to Bishop Thomas Byrne.

[4] He erected separate parishes for African Americans in El Dorado, Fort Smith, Helena, Hot Springs, Lake Village, Little Rock, North Little Rock, and Pine Bluff;[4] Morris also opened an African-American orphanage at Pine Bluff.

[4] Morris was confronted with a resurgence of anti-Catholicism early in his tenure, and during World War I many German American Catholics and German-speaking priests in Arkansas found themselves under suspicion.

[1] Morris, who was strongly patriotic and sold bonds during the war, helped mitigate such bigotry through his friendship with Arkansas Governor Joseph Robinson.

Morris opened Catholic High School for Boys in 1930, and was named an assistant at the pontifical throne the following year.