Middleman was born in Baltimore. He earned a B.A. in philosophy from The Johns Hopkins University in 1955, then studied at the Pennsylvania Academy of Fine Arts, the Skowhegan Summer School in Maine, and the Brooklyn Museum of Art School.
Since 1961, Middleman has taught painting and drawing at The Maryland Institute College of Art, where he chaired the painting department from 1975-1978. His murals of the different aspects of horse racing, done with his class, are on permanent display at the Pimlico Racetrack in Baltimore.
Middleman was president of the National Academy of Design from 1998 to 2001. He has shown his work at The Allan Stone Gallery, The Ice Gallery, MB Modern, and The Kouros Gallery in New York; The Roger Lapelle Gallery in Philadelphia; The Troika Gallery on the Eastern shore; and The C. Grimaldis Gallery in Baltimore.
Middleman has painted landscapes in oils, watercolors, and pastels in Brittany and the Ardeche in France; in Murnau, Germany; in Tuscany and Umbria, Italy; Scotland; the canyonlands of southern Utah; the seacoast of Buzzard's Bay, Massachusetts; and the embankments along the shores of the Susquehanna. The Katzen Gallery of American University has featured his paintings of narratives, portraits, and cityscapes, entitled "City Limits". His paintings can be found in private collections as well as through the Baltimore Museum of Art, the Metropolitan Museum of Art, the National Academy of Design, the Corcoran Gallery of Art, the National Gallery of Art, and the New York Public Library. In 2015, an exhibit of 374 self-portraits created by Middleman between 1959 and 2015 opened at the Maryland Institute College of Art.
Middleman has taught at the Vermont Studio School Summer Program; the International School of Painting, Drawing, and Sculpture in Umbria, Italy; and the Jerusalem Studio School in Israel. His work has been featured in solo and group exhibits in the MidAlantic area and Germany. He has won several awards for his work including the National Academy of Design’s Edward Palmer Prize in 2003 and was the 2001 artist in residence at the World Trade Center. He also served as president of the National Academy of Design from 1998 to 2001.