Complex sentence: When that did not pan out, DeBeck returned to Chicago and joined the "Chicago Herald" in December 1915, while working on a strip called "Finn an' Haddie" for the Adams Newspaper Service on the side.
Split into simpler sentences: When that did not pan out, DeBeck returned to Chicago and joined the "Chicago Herald" in December 1915. He worked on a strip called "Finn an' Haddie" for the Adams Newspaper Service on the side.