Reuben L. Hart was born in October 1865 in Pine Island, Minnesota.

The 1870 United States census showed Reuben Hart (age 4, born in Minnesota) living with his parents Lorenzo D. (age 52, born in New York, brick maker) and Louisa (age 46, born in New York) in Pine Island, Minnesota. His other siblings were Frances (age 17, born in Pennsylvania), Judson (age 15, born in Pennsylvania), John (age 12, born in Minnesota), and Lydia (age 8, born in Minnesota).

The 1875 Minnesota census showed Reuben Hart (age 9, born in Minnesota) living with his parents L. D. (age 58, born in New York) and Louisa (age 52, born in New York) in Minneola Township, Goodhue County, Minnesota. His other siblings were Frances L. (age 21, born in Pennsylvania), Judd (age 20, born in Pennsylvania), John (age 16, born in Minnesota), and Lydia (age 13, born in Minnesota).

The 1880 United States census showed Reuben L. Hart (age 14, born in Minnesota, brickyard worker) living in Pine Island, Minnesota. Reuben lived with his brother Judson (age 25, born in Pennsylvania, brick manufacturer), Judson’s wife Melinda A. (age 20, born in New York), Judson’s step-daughter Pearl L. (age 8 months, born in Minnesota), his parents Lorenzo D. (age 64, born in New York, brickyard worker) and Louisa (age 57, born in New York), and his brother John P. (age 21, born in Minnesota, brick manufacturer).

The 1885 Minnesota census showed Reuben Hart (age 19, born in Minnesota) living in Pine Island, Minnesota. Reuben lived with his brother H. J. (age 30, born in Pennsylvania), H. J.’s wife M. A. (age 25, born in New York), and H. J.’s children Pearl (age 5, born in Minnesota) and Frederic (age 1, born in Minnesota). Reuben’s parents L. D. (age 68, born in New York) and Louisa (age 61, born in New York) and his brother John P. (age 26, born in Minnesota) and John’s wife Sophia (age 25, born in Minnesota) also lived with the group.

Reuben Hart married Minnie M. Pike in 1888 in Minnesota.

The 1900 United States census showed Reuben Hart (age 34, born in October 1865 in Minnesota, brick maker) married to Minnie (age 29, born in September 1870 in Minnesota) and living in Mabel, Minnesota. Children Elizabeth (age 11, born in August 1888 in Minnesota) and Edith (age 8, born in March 1892 in Minnesota) also lived with the couple.

The 1905 Minnesota census showed Reuben L. Hart (age 39, born in Minnesota, brick maker) married to Minnie (age 34, born in Minnesota) and living in Pine Island, Minnesota. Children Elizabeth (age 16, born in Minnesota) and Edith (age 13, born in Minnesota) also lived with the couple.

The 1910 United States census showed Reuben L. Hart (age 44, born in Minnesota, brick maker) married to Minnie M. (age 38, born in Minnesota) and living in Pine Island, Minnesota. A daughter, Edith S. (age 18, born in Minnesota), also lived with the couple.

The 1920 United States census showed Rubin L. Hart (age 54, born in Minnesota, farmer) married to Minnie (age 49, born in Minnesota) and living in Milton Township, Dodge County, Minnesota. A son, Grant R. (age 7, born in Minnesota), also lived with the couple.

The 1930 United States census showed Reuben Hart (age 64, born in Minnesota, farmer) married to Minnie (age 59, born in Minnesota) and living in Milton Township, Dodge County, Minnesota. A son, Grant (age 17, born in Minnesota), also lived with the couple.

Reuben Hart died in 1953 in Williamsport, Pennsylvania.