Mary R. Moore was born on January 26, 1841, in Portage County, Ohio, to John and Clarissa Moore. Her father was a farmer who owned $1,400 of real estate and $2,555 of personal property by 1860. The family lived in Hiram, Ohio, until the 1850s, when they moved to Chester, Michigan. She married Ransom Chappell on June 14, 1868, and the couple had no children. They lived in Geneva, Michigan, and her husband worked as a farmer. By 1870, they owned $2,500 of real estate and $400 of personal property. By 1900, they employed at least one domestic servant. Her husband died on June 3, 1913. By 1920, she was living with her sister Lucy in Union City, Michigan. She died there of heart disease on March 20, 1920.