Irv Kosloff graduated from South Philadelphia High School in 1930, where he played football and basketball as an offensive center and middle linebacker.
Initially, he set out to be a dentist; however, he sustained a knee injury, and lost his athletic scholarship to Temple University, which he had attended for approximately two years.
Forced to drop out and search for a job due to financial problems, he found work in the traffic department of the Container Corporation of America in Manayunk, Philadelphia.
In 1932, he founded the Roosevelt Paper Company, which was located on State Road near Cottman Avenue in Philadelphia.
Kosloff, an executive who insisted on answering his own telephone and never hired a secretary, regularly attended Sixers games long after selling his stake in the team.