 He was the son of Henry Grafton Chapman Jr. (1833–1883), a broker who became president of the New York Stock Exchange, and Eleanor Kingsland Jay (1839–1921).His paternal grandmother, Maria Weston Chapman, was one of the leading campaigners against slavery and worked with William Lloyd Garrison on "The Liberator".His maternal grandparents were John Jay (1817–1894), the U.S. Minister to Austria-Hungary, and Eleanor Kingsland (née Field) Jay (1819–1909).