Lessing Julius Rosenwald (1891-1979) was a prominent American businessman, philanthropist, art collector, bibliophile, chess patron, and peace activist. Born in Chicago, Illinois, he rose to the position of vice president at Sears, Roebuck and Company, contributing to its growth during the early 20th century and serving as a former executive there. He was the uncle of Nina Rosenwald. Rosenwald's passions extended far beyond business; he amassed one of the world's foremost collections of rare books and fine prints, which he generously donated to the Library of Congress beginning in 1943, forming the foundational Lessing J. Rosenwald Collection of over 2,600 incunabula and illustrated books. A dedicated patron of chess, Rosenwald sponsored major international tournaments, including the Rosenwald Memorial events in the United States during the 1950s and 1960s, elevating the sport's profile. He also served as a trustee of the Carnegie Endowment for International Peace, reflecting his commitment to global harmony. In later years, he resided at his Alpenhof estate in Jenkintown, Pennsylvania, continuing his support for cultural and educational causes until his death in 1979.