John Davis Long rose from humble origins. He was born in Buckfield, Maine on October 27, 1838, and was educated in the Buckfield public school system. He then traveled south, earning his undergraduate degree at Harvard College in 1857 and his law degree at Harvard Law School in 1860. Long had accepted a Democratic nomination to run in the Massachusetts legislature, but he switched parties and was elected as a Republican to the state legislature in 1875.

He became lieutenant governor of Massachusetts in 1879 and was elected governor for three terms between 1880 and 1883. Long then ran successfully as a Republican for the U.S. House of Representatives, serving between 1883 and 1889 and sitting on the Shipping, Commerce, and Appropriations Committees.

He rose to serve in President William McKinley's cabinet when McKinley appointed him as secretary of the Navy on March 5, 1897. Long would retire on May 1, 1902 to write books and articles on the Navy and the Spanish-American War. Thereafter, he remained engaged in political debates, calling for abolition of the death penalty, and stumping for prohibition and women's suffrage before dying in Hingham, Massachusetts, on August 28, 1915.