Darius Holbrook Ingraham was born on October 14, 1837, in Camden, Maine, to Samuel and Mary Ingraham. His father was a trader who owned $2,400 of real estate and $1,000 of personal property by 1860. He grew up and attended school in Camden before enrolling at the United States Naval Academy. He was admitted to the bar in 1859, and he established a legal practice in Portland, Maine. He married Ella Moulton on June 25, 1868, and they had at least two children: Alice, born around 1870; and William, born around 1871. By 1870, he owned $3,500 of personal property, and he employed at least three white domestic servants.
He supported the Democratic Party, and he served in the state legislature in the late 1860s. He served as a United States consul in Cadiz, Spain, from 1885 until 1889 under Democratic president Grover Cleveland, and he was mayor of Portland in 1892. He also served as consul general in Halifax, Canada, from 1893 until 1897. He returned to Portland in the late 1890s and resumed his legal practice. His wife died on March 18, 1919, and he traveled to Spain and Gibraltar several months later for his “health.” By 1920, he was living with his daughter Alice in Portland. He died in New York on July 11, 1923.