The birth of modern stand-up comedy began in the Catskill Mountains - a boot camp for the greatest generation of Jewish-American Comedians. The birth of modern stand-up comedy began in the Catskill Mountains - a boot camp for the greatest generation of Jewish-American Comedians. The birth of modern stand-up comedy began in the Catskill Mountains - a boot camp for the greatest generation of Jewish-American Comedians. The birth of modern stand-up comedy began in the Catskill Mountains - a boot camp for the greatest generation of Jewish-American Comedians.