William Foster Morgan was born around 1828 in Gloucester, Massachusetts, to William and Gratia Morgan. His father was a fisherman. He married Eliza A. Pearson on June 24, 1852, and they had at least five children: Carrie, born around 1853; Luella, born around 1855; Susan, born around 1859; Elizabeth, born around 1860; and Delia, born around 1869. He worked as a cordwainer in Lynn, Massachusetts, and by 1870, he owned $200 of personal property.
He enlisted in the Union army on July 28, 1862, and he mustered in as a private in Company C of the 2nd Massachusetts Infantry on August 15. The regiment took part in the Battle of Antietam, the Battle of Gettysburg, the Atlanta Campaign, and the March to the Sea. He was wounded at Gettysburg on July 3, 1863, but he eventually recovered and rejoined the regiment. He was eventually promoted to corporal and then to sergeant. He mustered out on July 14, 1865.
Morgan returned to Lynn after the war, and he earned a living as a shoemaker. By 1870, he owned $1,000 of real estate and $200 of personal property. A decade later, he was working as a fisherman in Edgecomb, Maine. He died sometime after 1880.