William Aldred was born April 6, 1828 in New Castle County, Delaware.  He received a bachelor of arts degree from Dickinson College in 1856; as a student, he was a member of the Union Philosophical Society.  After graduation, Aldred retuned to Delaware and became a teacher.

At the outbreak of the Civil War, Aldred became a lieutenant in the 3rd Delaware Infantry; he later rose to the rank of adjutant.  He died at Front Royal, Virginia on August 8, 1862.