Although there were other post-season championships that took place as early as 1884, the World Series was not established until 1903--the year that the feuding National League and American League, who had been battling each other for several years over players, decided to come to some sort of peace agreement. They did not, however, make arrangements for a postseason series until August, when the Boston Pilgrims and Pittsburgh Pirates were already well in front of their respective leagues. The two teams agreed on a so-called "World's Championship Series"--a best-of-nine series which the Pilgrims won in 8 games, making them the first "modern" World Series champions.