David Henry Williams was a railroad surveyor, civil engineer and writer in civilian life. He was a volunteer in the United States Army during the Mexican–American War and a volunteer Union Army colonel during the American Civil War. He was appointed colonel of the 82nd Pennsylvania Infantry Regiment on July 23, 1861. He was appointed a brigadier general in the Union Army on November 29, 1862, but his appointment expired on March 4, 1863, without being confirmed by the United States Senate. His actual highest rank remained colonel. After the expiration of his appointment in 1863, Williams resigned from the Union Army and returned to his career as a civil engineer and, after his health soon declined, a writer for newspapers and magazines.