A descendent of both the Pepperell and Frost families of Kittery, Joseph A. Locke was born in Hollis, Maine on Christmas Day 1843.
Graduating with honors from Bowdoin College in the class of 1865, he taught at Portland High School for two years while pursuing his study of the law.
He was admitted to the bar in 1868 and joined the firm of Davis and Drummond, enjoying a successful practice before forming a partnership with his brother under the firm name of Locke & Locke in 1880.
He was elected to the Maine House of Representatives for two terms and was the Republican candidate for Speaker in 1879, being defeated by a coalition of Democrats and Greenbackers.
In 1880 he was elected to the Maine Senate and led the Republican opposition to attempts by the Greenback and Democratic parties to organize that branch.
As a result, Locke was elected President of the Senate at the age of thirty-seven, supplanting Jonas Wheeler as the youngest man to be elected to that position up to that time.
He was returned to the Senate in 1881 and reelected as President and, since this was the first session of the Legislature following the amendment to the Constitution providing for biennial elections, he was the first to serve for a two year term.
From 1883 to 1887 Locke was a member of the Executive Council before returning to his law practice and his two other interests, education and the Masonic fraternity, in which he held innumerable high positions.