Charles Gardiner Southworth was a resident of Mansfield on August 15, 1862 when he enlisted as a Captain in Co. D of the 21st Regiment Connecticut Volunteer Infantry; he resigned on November 24, 1862. Charles Southworth recruited 40 men for Co. D.

The descriptive muster roll of the 21st Regiment Connecticut Volunteer Infantry lists his age as 44 and his occupation as farmer.  He is described as 6’ tall with a fair complexion and dark eyes and dark hair.  His marital status is married. 

He was born January 23, 1815 in Mansfield, Connecticut to Samuel and Submit (Hartshorn) Southworth. In the 1860 U.S. census in Mansfield, he is a 45 year old farmer and head of household. Charles G. Southworth married Laura R. Swift on December 18, 1838 in Mansfield. Children include: Laura A. Southworth, born October 18, 1839; Ellen E. Southworth on April 23, 1841 and Samuel Southworth on March 12, 1845. He was a farmer in Mansfield until after 1870. Laura (Swift) Southworth died on July 29, 1871. In the 1880 U.S. census, Charles G. Southworth is living in the household of his son, Samuel in Longmont, Colorado. 

The date of death and burial place of Charles G. Southworth are unknown.