The Green Lantern Eating Cooperative, originally the Groves Cooperative Eating Club, was formed in February 1946 by a group of students and returning servicemen led by Terry Honda and Sid Dorros. The cooperative opened at 625 North Henry Street with 30 initial members, and postwar inflation in food costs spurred additional growth. In May 1946, the new cooperative moved to the basement of 1104 West Johnson Street and was renamed the Green Lantern Eating Cooperative in honor of a former organization on the site. Green Lantern shared facilities with the Groves Women's Cooperative House until the summer of 1963, when Groves moved to a new location on Gorham and Pinckney Streets. The University of Wisconsin bought the Johnson Street property, and Green Lantern sublet from the University's new tenant, Alpha Kappa Psi. Green Lantern moved to 604 University Avenue in 1964.
From the beginning, Green Lantern served meals to members and guests six days a week, financed by member fees, meal payments, and loan funds. Its stated purposes were to buy and prepare food for members, sell meals, own and operate restaurant equipment, buy personal property for members, and buy and sell real estate. A board of directors, consisting of the president, vice president, secretary, treasurer, and member-at-large, guided the cooperative with the participation of the membership. Permanent committees were established in the areas of education, social gatherings, membership, guests and substitutes, and menus. Temporary committees were established for canning, exchange dinners with other cooperatives, expansion plans, support for refugee families, and the budget. Other officials of the cooperative included a business manager, work chairman, cashier, bookkeeper, reporter, historian, and a full-time cook.
In its early days, the cooperative faced problems from the University of Wisconsin. The Green Lantern opposed the “in loco parentis” policies of the University, and university officials in turn sought to control the cooperative's membership and financial records. At one point, the Green Lantern was threatened with closing due to health and building code violations. Green Lantern continued, however, and established a tradition of involvement in community and political affairs. In the late 1950s and early 1960s, the cooperative was a haven for student and liberal causes and the organization was entered on Senator Joseph McCarthy's blacklist. As a result, many membership records for the period were destroyed. In the early 1960s, Green Lantern sublet space to the local National Association for the Advancement of Colored People and helped coordinate local participation in the Mississippi Freedom Summers. The Green Lantern also became a site for debate on the Vietnam War. In 1970, the cooperative set up free soup kitchens for striking teaching assistants at the University of Wisconsin. Green Lantern also served as the site of many benefit dinners, films, meetings, and financial solicitations.
The Green Lantern sought to encourage other cooperative ventures by purchasing from local organizations such as the Intra-Community Cooperative and the Mifflin Street Cooperative, and extended loans to the Groves Cooperative, Yellow Jersey Bicycle Cooperative, and the Madison Book Cooperative, and served as a model for the Rochdale Living Cooperative. Green Lantern also sponsored a film program since 1969, designed to introduce classic films to Madison audiences.
