Named for Hannibal Hamlin, President Lincoln's first Vice President, Hamlin is a triangular-shaped plantation in Aroostook County. Originally organized for election purposes on July 11, 1859, the plantation was formally organized on March 5, 1895. Prior to its organization, the township was known as Letter G R1 WELS.
Bounded by the St. John River, Hamlin is located just south of Van Buren, and served by United States Route 1-A.