Arch graduated in 1972 from the Harrisburg Academy. From 1972 to 1976 he studied Theater and Filmproduction at Emerson College in Boston, where he later had a production company. He established a friendship with cinematographer Conrad Hall, who was very influential in his life. Arch moved to Los Angeles in his early twenties, where he was a concert lighting designer while teaching himself how to write screenplays. In 1982 he married and moved to Virginia, and was teaching high school English and Tae Kwon Do when in 1990, he got the idea for "Sleepless in Seattle," after four unsold scripts and a failed off-Broadway attempt. Since the sale of the "Sleepless" script, he has written nonstop for virtually every studio in town, as well as producers Brian Grazer, Mark Johnson, Lauren Shuler-Donner, and directors Penny Marshall, Ron Howard and Barry Levinson. To date, four other movies have been made from Arch's scripts: Disney's "Iron Will," a production rewrite, "Sealed With a Kiss," an original romantic comedy for CBS," "Saving Milly," an adaptation of the Mort Kondracke memoir that scored a Humanitas Nomination for Arch's screenplay, and the indie comedy "Dave Barry's Complete Guide to Guys," which Arch also directed.