1840-1928 1887-1968 1915-1991 20thcentury abstractexpressionism american art artcollectionswalker artists biography blackinart catalogs catalogsmotherwell criticismandinterpretationmotherwell dadaism duchamp exhibitions history influence interviewsmotherwell marcel newyork newyork(state) newyorkschoolofart painters painting politicalaspects popart robert unitedstates worksmotherwell