Dr. William Levingston is the pseydonym for William Avery Rockefeller who was the father of John Davidson Rockefeller the richest man in America at the turn of the 20th century.
"Dr. William Levingston" was not a real medical doctor but rather a vendor of proprietary (patent) medicines. He was also a proven bigamist. In fact, that although he did not first get married until the age of 27, by being a bigamist William Avery Rockefeller was able to be married a total of 103 years even though he died at the ripe old age of 96.
He married, first onm Feb 18, 1837 at Niles, NY Eliza Davison.
He married, second, after 1889, Margaret L Allen.
Reference: Chernow, Ron. Titan: The Life of John D. Rockefeller, Sr. New York: Random House, 1998.
Note: He is buried in the Oak Knoll section of the Oakland Cemetery in Freeport, Illinois (findagrave.com)