Thomas Lees Dempster was born on 22. Dec. 1882 at Arlington, Fayette County, Iowa. He married
Bessie Amelia Monfore, daughter of
Edward Chapin Monfore and
Carrie Estelle Whipple, on 20. Sep. 1906. Thomas Lees Dempster was shown in the census on 18. Apr. 1910 as a farmer.
Thomas Lees Dempster and
Bessie Amelia Monfore appeared on the census of 18. Apr. 1910 at Springfield, Bon Homme County, South Dakota; 1 child, 1 living.

Thomas Lees Dempster was shown in the census on 28. Jan. 1920 as a farmer.
Thomas Lees Dempster and
Bessie Amelia Monfore appeared on the census of 28. Jan. 1920 at Springfield, Bon Homme County, South Dakota. Thomas Lees Dempster was shown in the census on 16. Apr. 1930 as a farmer.
Thomas Lees Dempster and
Bessie Amelia Monfore appeared on the census of 16. Apr. 1930 at Springfield, Bon Homme County, South Dakota. Thomas Lees Dempster died in Mar. 1976 his last known address was at Springfield, Bon Homme County, South Dakota, according to the SSDI.