Born Leo Joseph Mansowitz, Manso studied in the antique class at the National Academy of Design in 1930-31, and at the New School for Social Research, New York. During the early 1940s, he traveled and worked in Mexico and on Monhegan Island, Maine, and beginning in 1947, he spent his summers in Provincetown, Massachusetts. He was instrumental in that town's evolution as an art colony; was a founder of Provincetown's Gallery 256 in 1951 and the Long Point Gallery in 1977; and was a paticipant, with Jackson Pollock and Hans Hofmann, in the exhibition "Forum 19" in Provincetown.
Manso was best known as an abstract painter and, especially, as a leading collagist. He taught at Columbia University and New York University and, in 1976, joined the faculty of the Art Students League, New York, where he continued to teach until his death.
He won many awards including two Audubon Artists Prizes, a Ford Foundation Purchase, and a Childe Hassam Fund Purchase from the American Academy of Arts and Letters. A retrospective exhibition of his work was held at the Art Students League in 1992.
