Following his father's early death in 1864 from an illness contracted in battle during the U.S. Civil War that also killed his grandfather (during the Battle of the Wilderness in Virginia), his mother met and, in 1869, remarried to John George Adair, a Scottish-Irish businessman and landowner from County Donegal. After their marriage, they lived at Glenveagh Castle in Ireland, in Great Britain, and New York City, where Adair, also known as "Jack Adair", opened a brokerage house. His stepfather also owned a large cattle ranch, known as JA Ranch, southeast of Amarillo in the Texas Panhandle.