This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Assemblage spent forty years as a technique other movements used before it was widely treated as a category on its own. Dada artists including Marcel Duchamp, Hans Arp and Kurt Schwitters, whose Merzbau turned an entire house into an accumulating assemblage over more than a decade, all built with found and discarded materials in the 1910s and 1920s, but each is generally discussed under Dada first and assemblage second, if at all. The shift came with the American curator William Seitz, whose 1961 Museum of Modern Art exhibition The Art of Assemblage was the first major institutional attempt to name the technique as a coherent tradition running from Picasso's 1912 constructions through Rauschenberg's Combines, then showing at the same museum, and Cornell's boxes. Seitz's own catalogue essay is careful about what the show was and was not claiming: not a movement with a manifesto and a membership, the way Cubism or Surrealism had one, but a technique, a shared way of building an object out of the literal world's own discarded materials, that recurred across otherwise unrelated artists and decades because the same basic permission, that a work of art could be made of real things rather than only representations of things, kept proving useful to different people for different reasons.