A modicum of peace was eventually established, leading to the National Agreement of 1903. The pact formalized relations both between the two major leagues and between them and the National Association of Professional Base Ball Leagues, representing most of the country's minor professional leagues .  The World Series , pitting the two major league champions against each other, was inaugurated that fall, albeit without express major league sanction: The Boston Americans of the American League defeated the Pittsburgh Pirates of the National League.  The next year, the series was not held, as the National League champion New York Giants , under manager John McGraw , refused to recognize the major league status of the American League and its champion.  In 1905, the Giants were National League champions again and team management relented, leading to the establishment of the World Series as the major leagues' annual championship event.