1998 Major League Baseball expansion the American League. Following that transaction, MLB consequently altered its season structure so as to include interleague play throughout the regular season. 1998 Major League Baseball expansion The 1998 Major League Baseball expansion resulted in the establishment of Major League Baseball (MLB)'s 29th and 30th teams beginning play for the 1998 season. After initiating an expansion committee in March 1994, 27 groups representing nine cities submitted bids for the proposed expansion teams. After a yearlong process, on March 9, 1995, the league awarded the National League franchise to Phoenix and the American League franchise to Tampa. The Arizona Diamondbacks and
Baseball in the United States others. An extensive minor league baseball system covers most mid-sized cities in the United States. Minor league baseball teams are organized in a six-tier hierarchy, in which the highest teams (AAA) are in major cities that do not have a major league team but often have a major team in another sport, and each level occupies progressively smaller cities. The lowest levels of professional baseball serve primarily as development systems for the sport's most inexperienced prospects, with the absolute bottom, the rookie leagues, occupying the major league squads' spring training complexes and making no effort to earn money on their