In his 1945 presidential address to the American Historical Association, titled "The American Frontier—Frontier of What?", he urged Americans to see their nation as the western frontier of Europe. The Founders had maintained "lively contacts with, and solid knowledge of, the European civilization on whose boundaries they were". In the 19th century, with massive immigration from Europe, "Americans" took a different path from Europeans, becoming a nation of diverse linguistic, religious and ethnic origins, with each group desperate to be accepted. While nationalism in Europe emerged from an appreciation for the cultural or political achievements of one's compatriots, American nationalism encouraged fresh cultural and political developments. Hayes concluded that had produced an intense, and often artificial form of nationalism, that served to "inoculate us against Europe and built up an isolationist state of mind".Presidential address delivered at the annual meeting in Washington, D.C. on December 27, 1945. "American Historical Review" 50:2 (January 1946): 199–216. online</ref>