Mosse returned to farming his farm in Kickapoo, Kansas, in between his coaching jobs at Pitt and KU as well as later in 1914 when he retired from coaching. He came out of retirement for one year to coach at
Midland College in
Atchison, Kansas in 1918. He became well known throughout the state of Kansas and the country for breeding pure bred
Chester White hogs as he exhibited them at twelve state fairs across the country. He remained on the farm, where his daughters Marion and Ruth were born, until 1924 when he and his wife moved to
Van Nuys, California, to be near their daughter, Justine. Justine also attended the University of Kansas and had played on the first "mythical" varsity
Kansas Jayhawks women's basketball team in the school's history in 1920 as a freshman. As women were not then allowed to play intercollegiate basketball the team was not technically an official varsity team being picked by the faculty and they only played intramural games against other women's organizations on campus. His wife, Ruth, died on December 11, 1928, in
Los Angeles, California, whereupon Mosse moved in with his daughter, Justine also living in Van Nuys, California, at the time. Despite having lived in the
United States for nearly 50 years, Mosse did not officially become a naturalized US citizen until January 8, 1937, in Van Nuys, California. Later in 1944 he and his daughter moved to
San Diego, California, where Mosse died on January 8, 1956, at the home of his daughter. He was survived by his daughters Justine St. Leger Mosse (November 9, 1899 – May 11, 1986), Mrs. Marion Wellesley Russell (November 5, 1903 – November 22, 1994) and Ruth Grover Mosse (October 10, 1911 – 2003). Mosse was buried in
Oak Hill Cemetery in Lawrence, Kansas, next to his wife. ==Head coaching record==