Quincy (Josiah III) is born in Boston.

The son of Josiah Jr. and Abigail (Phillips) Quincy, Josiah Quincy III graduates from Harvard College, becomes a lawyer, and marries Eliza Susan Morton in 1797. He lives at 5 Park street. Quincy serves in the Massachusetts Senate (1804-05), the U.S. House of Representatives (1805-13), and the Massachusetts Senate (1814-19), speaker of the Massachusetts House of Representatives (1820), Boston Municipal Court judge (1821), and as mayor of Boston (1823-29). Called “The Great Mayor” for his accomplishments in office, he then serves as president of Harvard College (1829-45), and, upon his retirement, becomes a writer of local history. He dies in Quincy on July 1, 1864, and is buried in Mount Auburn Cemetery.