After becoming an editor at Marvel, McDuffie submitted a spoof proposal for a comic entitled "Teenage Negro Ninja Thrashers" in response to Marvel's treatment of its black characters. Becoming a freelancer in 1990, McDuffie wrote for dozens of various comics titles for Marvel, DC Comics, and Archie Comics. In addition, he wrote "Monster in My Pocket" for Harvey Comics editor Sid Jacobson, whom he cites on his website as having taught him everything he knows. In early 1991, he divorced his first wife, Patricia D. Younger, in Seminole County, Florida.