While there are many histories of unions in the United States, there are relatively few studies of employer associations and their role in industrial relations. Howell John Harris's recent study of the Metal Manufacturers Association of Philadelphia, Bloodless Victories: The Rise and Fall of the Open Shop in the Philadelphia Metal Trades, 1890–1940 (New York: Cambridge University Press, 2000), stresses the importance of values in shaping employer behavior. William Millikan's meticulous history of the Minneapolis Citizens Alliance likewise demonstrates the importance of ideas as well as interests in business approaches toward industrial relations. The Minneapolis employers, however, embraced a tougher brand of anti-unionism than Harris found in Philadelphia.