He did dozens upon dozens of plays, off-off-Broadway, off-Broadway, and finally on Broadway. He won the Obie Award, the Villager Award, the Dramalogue Award, the Clarence Derwent Award, and was nominated for a Drama Desk Award. "These were great years, but the best thing that happened to me occurred on the night of July 3rd, 1976. I was doing Henry V in the park, and after the show a friend introduced me to a beautiful young artist named Marni Bakst. We sat on a stone wall in Central Park and watched the Bicentennial fireworks -- well, at least she watched the fireworks. We were married a year later and I'm happy to report we're still going strong. She is without question the best thing that ever happened to me. She's still my harshest critic, my biggest booster, and my best friend."

Bill's years in the New York theatre climaxed with a year and a half on Broadway in Neil Simon's Biloxi Blues, in which he played the crazy southern drill sergeant Merwyn Toomey opposite Matthew Broderick. When Broderick left to do Project X, Bill got the call to play the head of the cruel air force research project that nuked chimps to see how long they could function while dying of radiation poisoning. While not a huge hit at the box office, the film did get Bill in front of the cameras for the first time and introduced him to a whole new market for his talents -- Hollywood.