Walter Arnstein served as Professor of History in the History department at the University of Illinois at Urbana-Champaign from 1968 until his retirement in 1998 as Professor of History Emeritus and Jubilee Professor of the Liberal Arts and Sciences Emeritus. Born on May 14, 1930, in Stuttgart, Germany, he emigrated to the United States with his family in 1939 and became a naturalized citizen in 1944. Arnstein earned a B.S.S. magna cum laude from the City College of New York in 1951, an M.A. from Columbia University in 1954, and a Ph.D. in history from Northwestern University in 1961, following a Fulbright fellowship year at the University of London. He served in the U.S. Army from 1951 to 1953, including duty in Korea as an assistant battalion supply sergeant. Before joining UIUC, he taught at Northwestern University, the University of Chicago, and Roosevelt University, rising to Dean of the Graduate Division there. At UIUC, he chaired the department, directed graduate studies, supervised twenty-five Ph.D. dissertations in British history, and taught British history at all levels from introductory surveys to doctoral seminars. He held visiting fellowships at the University of Cambridge and the University of Edinburgh.

A specialist in modern British history, Arnstein authored key works such as The Bradlaugh Case (1965), Protestant Versus Catholic in Mid-Victorian England (1982), the longstanding textbook Britain Yesterday and Today: 1830 to the Present—which for over four decades introduced more American and Canadian students to modern British history than any other—Queen Victoria (2003), and compiled The Past Speaks: Sources and Problems in British History Since 1688 (1981). He published more than forty-five journal articles and 170 book reviews. Arnstein received numerous teaching awards and was elected a Fellow of the Royal Historical Society. He served as president of the Midwest Victorian Studies Association, which established the annual Arnstein Prize for graduate student papers in 1990, and as one of the first presidents of the North American Conference on British Studies. He sat on the editorial boards of The Historian, Albion, and Victorian Studies. Arnstein founded and frequently hosted the British History Association, an off-campus organization that engaged generations of UIUC students through meals, lectures, and social events. He passed away on October 6, 2019.