Paine III (Robert Treat) is born in Boston.

The son of attorney Charles Paine and great grandson of Judge Robert Treat Paine , Robert Treat Paine graduates from Boston Latin School, Harvard College, and Harvard Law School. He initially practices real estate law, then invests successfully in mining, railroads, and western real estate. Paine marries Lydia Lyman in 1862, and lives at 6 Mount Vernon Place and at Stonehurst in Waltham. After retiring in 1872, he spends the rest of his life engaged in philanthropy, building housing for the poor, and as pacifism, subsequently writing, “We had this life on earth only once [and] I was not willing to devote the last half of it to the mere business of making money.” Paine dies on August 14, 1910, and is buried in Mt. Auburn Cemetery