 Morgan was born in Clifton, Staten Island on September 24, 1860 and was named after his maternal grandfather.He was a son of "eminent banker" David Pierce Morgan (1831–1886) and Caroline (née Fellowes) Morgan (1832–1914).Among his siblings was Clara Hewitt Morgan, David Percy Morgan (treasurer of American Sugar Refining Company, brother-in-law of Herbert Parsons and son-in-law of John Edward Parsons), Alice Morgan (wife of diplomat John Ridgeley Carter), and Lewis Henry Morgan.