The Atlantic League of Professional Baseball is a professional, independent baseball organization located primarily in the Mid-Atlantic and Northeastern United States, especially the greater metropolitan areas of the Northeast megalopolis. It operates in cities not served by Major or Minor League Baseball teams and is not affiliated with either. The Atlantic League requires cities to have the market for a 4,000 to 7,500-seat ballpark and for the facility to be maintained at or above AAA standards. When Atlantic League professionals are signed by MLB clubs, they usually start in their Double-A or Triple-A affiliates.
In 1998, the Atlantic League of Professional Baseball played its inaugural season, with teams in Somerset, Newark, and Atlantic City (NJ), Nashua (NH), Newburgh (NY), and Bridgeport (CT). The creation of the league was the result of the New York Mets' objection to Frank Boulton's proposal to move the former Albany-Colonie Yankees because of its territorial rights to the region. Boulton, a Long Island native, decided to create a new league that would have a higher salary cap for its players and a longer season than most of the other independent baseball organizations. He modeled the Atlantic League after the older Pacific Coast League, with facilities that exceed AAA-level standards. Boulton also emphasized signing players of Major League Baseball experience for all Atlantic League teams, raising the level of play above other independent leagues.