Max Riebenack (1844-1910) immigrated from Bavaria as a child. At age 19, he began working for the Pennsylvania Railroad, eventually rising to the position of Controller of the Railroad and all of its subsidiary lines. He and his family lived at 3701 Powelton Ave. from the 1870s until 1889. He then built the mansion at the corner of 34th St. and Powelton Ave. (227 N. 34th St., now Drexel University's Ross Commons) where he lived until his death in 1910.
One measure of his social position is his club memberships. According to the 1906 edition of Boyd's Blue Book, he was Treasurer of the Union League, President of the Five O’Clock Club (927 Chestnut St.) and a member of the Merion Cricket Club, the Belmont Cricket Club, the Philadelphia Yacht Club and the Powelton Club (209 35th St.). According to a history of the Five O'Clock Club written in 1891, it was a social club founded in 1883 that was initially composed of "well-known newspaper, railroad, theatrical and other professional and business men." It is hard to tell from this list how sociable he was, but he was certainly well-connected.