 After a few years, he left to freelance, selling cartoons to "World" editor John Tennant.In 1916, the George Matthew Adams Service syndicated Crosby's first feature, the daily and Sunday strip "The Clancy Kids", earning Crosby a respectable $135 a week.While continuing on this first strip, Crosby studied at Manhattan's Art Students League under such instructors as George Bridgman, Frank DuMond, Joseph Pennell and Max Weber.