Rea married Mary Black, the daughter of Jane Black, in 1879. In 1880, Samuel and Mary lived with her widowed mother and family in Allegheny, Pennsylvania. Their children, born after 1880, include George Rea and Ruth Rea. Rea was a member of the exclusive South Fork Fishing and Hunting Club, whose earthen dam failed in May 1889, causing the Johnstown Flood. After the flood, Rea removed to Bryn Mawr, Pennsylvania, to an estate called "Waverly Heights," designed by architect Addison Hutton. Waverly Heights later became a lifecare community in Gladwyne. Rea was reared in the Presbyterian faith and said he preferred reading Prof. Moffet’s translation of the Bible. He died at his home in Gladwyne, Pennsylvania on March 24, 1929.