American sculptor. Studied at the Phillips Academy in Andover between 1951 and 1953. In 1957 he moved to New York, where he began writing poetry. He also produced sculptures and painting in wood and acrylic. He met Frank Stella in 1958 with whom he shared a studio after 1959 and whose canvases (Black and White), together with Brancusi's works, inspired him to create his first large sculptures. As from 1965, he produced sculptures based on building materials, becoming part of the minimalist movement. This artist's sculptures are not to be seen in isolation but within their architectonic settings. Since 1967, he has applied his modules technique to sculptures in metal and produced compositions with slabs of earth or aluminium one can walk along. In 1968, he took part in documenta 4 in Kassel and the Minimal Art exhibition at the Gemeente Museum in The Hague. In 1982, he took part in documenta 7 in Kassel.