Warren Wightman Packer was born on February 1, 1835 in Groton, Connecticut. He was a clerk there before the war.

On July 23, 1861, he became Captain of Company G in the 5th Connecticut Infantry Regiment. He was wounded in the right thigh at the Battle of Cedar Mountain on August 9, 1862. His promotion to Major dated to that day.

He became Colonel in January of 1863, replacing Col. George D. Chapman, who was forced to resign due to severe illness. Packer was captured at Chancellorsville but was paroled, returning on June 12 to commanded the regiment at Gettysburg.

In July of 1864 he took over the 1st Brigade of the 1st Division of the 20th Army Corps. He was mustered out on October 20, 1864 with the expiration of his enlistment.

He returned to Mystic, Connecticut, where he served 17 years as Postmaster. He died there on December 27, 1912, and is buried in Elm Grove Cemetery.