Tupperware, plastic containers with tightly locking lids, transformed the way food was stored (as well as the way brands sold their wares). But Tupperware did something else, too: It helped reinvigorate a food tradition with ancient roots, and maybe even helped spur on the feminist movement. But as America settled into an era of prosperity following World War II, potluck meals began to fall out of fashion. It was around 1942 that Tupper first produced the flexible, injection molded polyethylene that would become the stuff of Tupperware. “I believe very strongly in building community through shared meals and I think potlucks are a really good way to do it,” says Brumberg-Kraus.