The concept of the teach-in was developed by anthropologist Marshall Sahlins of the University of Michigan at Ann Arbor during a meeting on March 17, 1965. Previously, around 50 faculty members had signed onto a one-day teaching strike to oppose the Vietnam War. About a dozen of these faculty members, including William A. Gamson, Jack Rothman, Eric Wolf, Arnold Kaufman, and Roger Lind, reconsidered the strike and gathered to discuss alternative ways to protest the war in the face of strong opposition to the strike from the Michigan legislature and governor as well as the university president. The New York Times Magazine summed up how Sahlins arrived at the idea: "They say we're neglecting our responsibilities as teachers. Let's show them how responsible we feel. Instead of teaching out, we'll teach in—all night."
