Charles G. Strahan was born around 1826 in Pennsylvania. He married Harriet Thurber, and their son Edwin was born around 1852. They also adopted a daughter named Martha, who was born around 1842. They lived in Providence, Rhode Island, and Strahan worked as an actor.
He enlisted in the Union army on April 17, 1861, and he mustered in as a private in Company G of the 1st Rhode Island Infantry on May 2. He was promoted to sergeant on May 21, 1861, and he took part in the First Battle of Bull Run. The regiment mustered out on August 2, 1861.
Strahan returned to the Union army in October 1861, receiving a commission as a captain in Company I of the 3rd Rhode Island Heavy Artillery. The regiment took part in the siege of Charleston, and he mustered out on August 31, 1864.
He settled in Texas after the war. He applied for a federal pension in August 1882, but he apparently never received one. He died sometime after August 1882.