After graduating from Gettysburg College with an English degree, Spinelli worked full time as a magazine editor. Every day on his lunch hour, he would close his office door and craft novels on yellow magazine copy paper. He wrote four adult novels in 12 years of lunchtime writing, but none of these were accepted for publication. When he submitted a fifth novel about a 13-year-old boy, adult publishers once again rejected his work, but children's publishers embraced it. Spinelli feels that he accidentally became an author of children's books.