Simon was born Simon Bacharach in Germany. After immigrating to the United States in 1857, he and his brother Nathan changed their surname to Barnum and moved west to Kansas; Nathan to Newton and Simon to Topeka. The name change may have been to make it easier to do business in the 19th century, as Bacharach is a recognizably Jewish surname. However, even after the name change they were both active in the Jewish community in Kansas.
Bacharach, also Bachrach, is a German surname, mostly Jewish, referring to the medieval town of Bacharach in the Mainz-Bingen district of the Rhineland-Palatinate.
Simon applied for a US Passport in Philadelphia, Pennsylvania, on 24 April 1883, at the age of 40.
JewishGen Online Worldwide Burial Registry (JOWBR). Name: Simon Barnum; Birth Date: 2 May 1842; Death Date: 15 Jul 1907; Age at Death: 65; Burial Date: 16 Jul 1907; Burial Plot: J-13-4; Burial Place: Topeka, Kansas, USA; Cemetery ID: USA-02842; Spouse Name: Barnum, Emma; Cemetery: Topeka Cemetery; Cemetery Address: 1601 SE 10th Ave.; Photo: Image Available.