This family was enumerated in the 1880 US Census for White, Union County, Arkansas. The will of Barnum, Marvin Sr. was written November 25, 1905 and filed August 31, 1914. It was witnessed by Alexander M. Wilson and appears in Hamilton County, IL Wills and Probate Papers Index, Papers to 1900 (Wills to 1915).
27 Aug 1914 Issue of the Times (McLeansboro, IL). Barnum, Marvin; born 22 Oct 1828 in Johnstown, Ohio; died 25 Aug 1914 at home of daughter, Mrs. R. L. Boyd, McLeansboro; son of Joseph and Electa C. Barnum, both died in 1865. Married Mrs. Harriet Gwin Biggs, New Albany, Indiana; 4 children: Williard A. Barnum, Rend City; Wiley B. Barnum, Ridgway; Marvin H. Barnum, Norris City; Mrs R. L. Boyd, McLeansboro. Shipbuilder in early life, later a carpenter. Moved to McLeansboro about 1884 from Beebe, Arkansas. Interred IOOF Cemetery, McLeansboro.
He was buried in the Odd Fellows Cemetery.