In 1891, Mann moved to
Kansas City, Missouri, and worked as a cashier at the Holland Shoe Company. In the winter of 1891, Mann moved to
Minot, North Dakota, and he became the editor of the
Minot Journal. He worked as editor for three and a half years. He was appointed as city clerk of Minot and served two terms. In 1896, Mann was appointed to a clerkship by Mayor
James M. Jones. He was then appointed as Superintendent of Sidewalks and Curbing. Homer was a
Republican. He was elected to the
Missouri House of Representatives, representing the 2nd district, in November 1898. Mann was later re-appointed as Superintendent of Sidewalks and Curbing. In Spring of 1900, Mann joined the W. S. Dickey Clay Company. He remained with that company until February 1904. He later organized the firm Trout & Mann, a fire and accident insurance business. Mann worked with P. S. Brown and Sons Insurance Company (later Brown & Mann), joining as a junior member in 1904. His insurance company later was renamed the Mann, Kerdolff, Kline & Welsh firm. In 1902, Mann was elected to the lower house of the
Kansas City, Missouri City Council. He served two terms and one as speaker. Mann served as the treasurer of the Republican County Central Committee and served as delegate to the Missouri State Conventions for about ten years. Mann served as president of Park College for 25 years. He served on the board of trustees of Park College for 33 years. Mann retired as president of the board of trustees in 1939. ==Personal life==