After leaving Oberlin College in 1860, James Prosser Osbourn became a very important and prominent restaurant owner and had a very impressive catering company that would go on to cater to many important events within the United States. Catering became an important avenue for many prospective black business owners in Philadelphia. Catering was previously something aimed at the upper classes of society, and the Prossers among other families would become well known in social circles for aiming their businesses at the growing middle class. This would make the Prosser a household name for at least 50 years. Aside from the monetary incentive, catering became a powerful political tool. The catering business became a way to rebuild black collations and unify the city after a series of vicious race riots. These riots led to increased levels of crime and worse conditions within the cities slums that were mostly inhabited by Black Philadelphians (The Philadelphia Negro 32-36).
One conflict that came from Prossers newfound fame would be from the white dominated Philadelphia Sportsmen Club. This group of games men would go around and write black businesses citations for selling animals that were out of season. One highly published interaction came when this group charged him with selling quail out of season, when Presser claimed he sold the man Squab instead. Presser would then attempt to settle the matter in court, though it is unclear if he was successful in getting the charges dropped (Philadelphia Times Jan 14th 1878).
Another one of the many impressive things that James Prosser was involved with was a club by the name of "Welcome Club" which was indirectly a part of the inauguration of President James Garfield. During this event another student that attended Central College, Benjamin Kellog Sampson was heavily involved with its organization (student paper).
James Prosser Osbourn would go on to marry Mary E. Wilson, although not much is known about her earlier life, the two would go on to have two children, James Prosser Osbourn Jr. and Stella Osbourn. His son James Prosser Jr. was born in 1866 and his daughter Stella was born in 1868. James Sr. would pass away at the age of 48, on August 30th 1892(dropbox).