He trained as a pharmacist and doctor, and became wealthy by selling patent medicines such as 'Ayer's Sarsaparilla.' He owned stock in textile mills, railroads, and newspapers, and funded the American Woolen Company, helmed by his brother Frederick, which became the largest manufacturer of woolens in the United States. The town of Ayer, Massachusetts is named for him, though the residents of the town held a public burning of his effigy after he ran for Congress in 1874. He died in an insane asylum in 1878.