William Addison Pitt Dillingham was born on September 1, 1824, in Hallowell, Maine, to Albert and Elizabeth Dillingham. He attended Harvard University in the mid-1840s, and he married a woman named Caroline. They had at least three children: Mary, born around 1848; Thomas, born around 1851; and Pitt, born around 1853.
He was ordained as a Universalist minister in October 1847. They lived in Dover, Maine, and by 1850, he owned $2,100 of real estate. They moved to Portsmouth, New Hampshire, and then to Sidney, Maine, in the 1850s. By 1860, he owned $7,000 of real estate and $4,000 of personal property.
He supported the Union Party during the Civil War, and he was elected to the state legislature in 1864. In October 1864, he received a commission as an “agent for the freedmen.” He became speaker of the Maine House of Representatives in 1865. Soon afterward, he received an appointment as a treasury agent “to take charge and dispose of confiscated rebel property in Mississippi.”
After the Civil War, he served as vice president of the Maine Freedmen’s Relief Society. He continued his work as a minister in Sidney, and by 1870, he owned $8,500 of real estate and $3,000 of personal property. According to an early biographer, he “took a deep interest in agriculture, education and all public enterprises, giving them a strong and earnest support.” He died in Sidney of pneumonia on April 22, 1871.