The collection of the former Cologne gallery owner and collector Rolf Ricke focusses on works of American Post-Minimalism and conceptual art. Assembled from the 1960s onwards in close cooperation with the artists – most of them exponents of the New York art scene – it not only played a pioneering role in the reception of contemporary American art in Europe, but also encompasses a large number of works of considerable art-historical importance. Included are examples by Richard Artschwager, Jo Baer, Bill Bollinger, Harriet Korman, Gary Kuehn, Barry Le Va, Lee Lozano, Richard Serra, Paul Sharits, Keith Sonnier, Lewis Stein, David Reed and Günter Umberg as well as artists of the following generation such as Jessica Diamond, Thom Merrick, Cady Noland, Carl Ostendarp and Steven Parrino. In 2006, the MMK, the Kunstmuseum Liechtenstein and the Kunstmuseum St. Gallen together acquired the collection. In many respects, it built on the existing MMK collection, enriching it with a range of new resonances and references.