[1] After the war he earned a BFA degree at Yale University, where he studied with Josef Albers and Willem de Kooning.
During that time he also founded the Stewart-Marean Gallery and The Stewart Studio, which was established for the design and execution of his commissioned mosaic furnishings and murals.
[3] Stewart's work is in major private and public collections including: The National Academy Museum, NYC; New-York Historical Society, NY; The Museum of the City of New York, NY; Ogden Museum of Southern Art, New Orleans, LA; New York University, NY; Yale University Art Gallery, CT; Wesleyan College, Macon, GA; Greenville County Museum of Art, Greenville, SC; Columbia Museum, Columbia, SC; Indiana State University, IN; Miami University, FL; the Museum of Southeast Missouri University, MO; Rosemary Berkel & Harry L. Crisp II Museum, Southeast Missouri State University, MO; The Gwinnett Fine Arts Center, Duluth, GA; Jacqueline Casey Hudgens Center for the Arts, Duluth, GA; EMP Museum (Experience Music Project), Seattle, WA; and the Savannah College of Art and Design, GA. Stewart's mosaic furniture designs were often featured in the books published by Furniture Forum Inc. His work was also featured in the magazine House & Garden and on the cover of the January 1960 issue of House Beautiful.
His many commissions for mosaic and ceramic tile murals and stained glass windows included: a 17' x 92' long mosaic on the facade of the Versailles Hotel, Miami Beach, FL; the Hotel Aruba Caribbean, Netherlands, Antilles; eleven mosaics murals for the SS Santa Paula; mosaic murals in Public School 28, NYC, NY, Public Art for Public Schools;[4] a stained glass window installation for Robin International Corporation of NYC; a 5' x 18' long laminated stained glass wall for Avard Furniture Company, NYC; and in 1988 he was commissioned to create a 4' x 18' mural made of clothing labels, sheepskin, and cotton balls for the Cluett Arrow Shirt Group of New York City.
Stewart also wrote about the colossal carving of Chief Crazy Horse, The Tribune-Star, Terre Haute, IN, 1978; articles on drawing and mosaics for the Thomas Jefferson Encyclopedia, World Publ.
He was chairman of the art departments of The Cooper Union and Indiana State University, and Vice President and Provost of the Rhode Island School of Design.
[Stewart directed the English-speaking division of the Athens Advanced School of Fine Arts in Mithymna on the island of Lesbos during the summers of 1963 and 1964.]
"[14] Though Stewart had a thorough grounding in all aspects of techniques–sculpture, printmaking, watercolors, egg-tempera, oil, ceramic fresco, and mosaics–he adopted acrylics as a preferred medium in the early 1960s and experimented with them in a way that led to a kind of painting that is technically different from anything else.
In an article about Anodyne in Il Giornale dell'Arte, artist/art critic Lucio Pozzi wrote: "What comes out of this, in my opinion, is one of the most monumentally important works of symbolist-precisionist painting of our time.
In the fall of 1969 and the spring of 1970 graffiti started to appear on New York subway station walls and inside the cars, and that is when Stewart began to photograph and research this urban phenomenon.
The most thoroughly and intensely studied period was the winter of 1972 through the spring of 1973 when Stewart unfailingly photographed every weekend in order to compile and identify the constantly changing, distinguishing characteristics as they were happening.
Abrams published the thesis in 2009 under the title Graffiti Kings: New York City Mass Transit Art of the 1970s.
Duncan Bock, editor-in-chief of Melcher Media, the firm that helped bring Graffiti Kings to a popular audience, described Stewart's work: 'Jack understood the intensity, beauty and importance of the tags, why they were on trains, and why it was so hard to do it well.
"Graffiti Kings is the best record of the month-by-month evolution of subway graffiti in the seventies, starting with the red subway cars that were largely retired by the eighties and moving through all the 'firsts' and stylistic phases: tags, outlines, masterpieces, 3-D letters, bubble letters, and the first attempts at what eventually became 'wild style.
'"[16] Stewart's work has been written about, quoted, and reproduced in many publications including: Born in the Streets: Graffiti, Fondation Cartier pour l'art Contemporain, 2009;[17] Graffitins Historia by Malcolm Jacobson, Sweden, 2011;[18] 365 Graffiti, by Jay "J.SON" Edlin & Andrew "Zephyr" Witten, Abrams, 2011;[19] Art in the Streets, Jeffrey Deitch, et al., Skira Rizzoli/MOCA, 2011;[20] Graffiti une Histoire en Images by Bernard Fontaine, Eyrolles, Paris, France, 2011;[21] Classic Hits: New York Pioneering Subway Graffiti Writers by Alan Fleisher & Paul Lovino, Dokument Press, Sweden, 2012.
3–4, pages 40–49, the New York regional collections specialist Charles H. Duncan referred to Stewart as Graffiti's Vasari.