- Father: Alexander Mattson b. 2 September 1869, d. 27 January 1924
- Mother: Emma Josefina Reini b. 3 May 1872, d. 23 August 1939
- Theodore Mattson was born.
- Theodore Mattson died.
- He was interred at South Lead Cemetery, Lead, Lawrence County, South Dakota.
- A single grave marker identifies the graves of Alexander Mattson and Emma Josefina Reini and Theodore Mattson, Wilho Edward Mattson, George Mattson and Ida Mattson.
- Last Edited: 15 Jul 2016