From 1971 to 1972, Welch created performance works at 112 Greene Street and had his first significant one-person exhibition at 98 Greene Street, an alternative art space run by Holly Solomon. Among his friends and colleagues at this time were Bill Beckley, Les Levine, Gordon Matta-Clark, William Wegman, and Hannah Wilke. Welch also began to work primarily in multi-media and created a three-channel video Passing On. In 1972, Welch had solo exhibitions at Sonnabend Gallery in Paris, Konrad Fischer in Düsseldorf and Yaki Kornblit-Galerie 20 in Amsterdam. During his 1973 solo exhibition at the John Gibson Gallery in New York, Welch produced a series of maps drawn from the childhood memories of four elderly people. On consecutive Saturday afternoons over the course of the exhibition, Welch engaged in a dialogue with each person about her or his hometown while he created drawings and a map from their verbal recollections. Visitors could attend the sessions and view previously completed maps and drawings. This exhibit was followed by a solo show at the Milwaukee Art Museum which featured the Kitty Ewens Memory Map. The work was created from the childhood recollections of Kitty Ewens, a 101-year-old resident of the Milwaukee area. The Memory Maps attracted the attention of social psychologists such as Stanley Milgram with whom Welch collaborated in a 1975 exhibition at the Piltzer Gallery in Paris. Beginning in 1974, Welch devised the video installation The Roger Woodward Niagara Falls Project also known as The Niagara Falls Project. The work was completed in 1975 and exhibited at the Steffanoty Gallery in New York. Two subsequent video installations, Preliminaries, exhibited in New York at the M.L. D'Arc Gallery in 1976 and the O. J. Simpson Project at the Albright-Knox Art Gallery in Buffalo, New York extended his explorations in multi-media. In 2008, The O. J. Simpson Project was exhibited at the Museo Nacional Centro de Arte Reina Sofia in Madrid. At the beginning of the 1980s, Welch created two film and sculpture installations, Drive-In, shown at MoMA PS1, Long Island City, New York, in 1980 and Drive-In: Second Feature shown at the Whitney Museum of American Art in 1982. John Hanhardt, Whitney Museum Curator of Film and Video, selected Welch's work to inaugurate The New American Film Makers Series. Drive-In: Second Feature has been exhibited in museums and public institutions in the United States, Europe and, in 2007, at the Museum of