Green (Samuel A.) is born in Groton.

Descended from a family that came to America in 1636, Samuel Green graduates from Harvard College, becomes a doctor a doctor in Boston in approximately 1850, and serves as a surgeon during the Civil War. Returning to Boston, he is elected to the School Committee, serves as acting librarian of the Boston Public Library, city physician, and mayor of Boston (1882). Green lives at 35 Kneeland Street. He later serves as librarian of the Massachusetts Historical Society. Green dies on December 5, 1918.