William Ellis Endicott was born on April 1, 1842, in Canton, Massachusetts, to John Endicott and Ann Matilda Ellis. His father was a farmer who owned $1,500 of real estate in 1850. His father probably died in the early 1850s. Endicott grew up and attended school in Canton, and he began working as a teacher in 1859.
He enlisted in the Union army on August 16, 1862, and he mustered in as a private in the 10th Massachusetts Light Artillery on September 9. As he explained to his cousin, he enlisted “from the three fold influence of bounty[,] fear of the draft[,] and shame at being at home.” The battery took part in the Battle of the Wilderness, the Battle of Spotsylvania Court House, the Battle of Cold Harbor, and the siege of Petersburg. Confederate forces captured him near Reams’ Station, Virginia, on August 25, 1864, and imprisoned him in Libby Prison in Richmond, Virginia. He eventually received a parole, and he mustered out on June 9, 1865.
Endicott returned to his mother’s household in Canton after the war and resumed his work as a teacher. By 1870, he owned $2,000 of personal property. He married Emma Williams in Boston, Massachusetts, on December 28, 1870, and they had at least two children: Louise, born around 1874; and John, born around 1877. By the early 1870s, he was working as “school master” of the Christopher Gibson Grammar School in Boston.
He also served as the librarian of the Massachusetts Horticultural Society. He remained in Canton for the rest of his life, eventually becoming one of its “foremost citizens.” His wife died in 1902. Endicott was involved in an “electric car accident” in Boston around May 1903. He died of heart failure in Canton on June 3, 1903.