William Augustus Hollis was born on November 21, 1837, in Massachusetts to Joel and Mary Hollis. His father was a farmer and boot maker who owned $2,000 of real estate and $500 of personal property by 1860. Hollis grew up and attended school in Braintree, Massachusetts, and by 1860, he was working as a boot maker. He married Hannah Adeline Holbrook on September 28, 1858, and they had at least two children: Ellsworth, born around 1864; and Omer, born around 1868. They lived in Braintree, and Hollis continued to work as a boot maker. In 1870, his brother Albert was living in his household. He remained in Braintree for the rest of his life, and he retired sometime in the 1890s. He died of toxemia in Braintree on March 16, 1901.