In addition to New York and Pennsylvania, from which the league drew its name, the NYPL also had clubs in Maryland, Massachusetts, Ohio, Vermont, West Virginia, and Connecticut.

The original teams included the Batavia Clippers, Bradford Bees, Hamilton Red Wings, Jamestown Jaguars, Niagara Falls Rainbows, and Olean Oilers; all were based in or near Western New York.

The Hamilton Red Wings folded early in the 1956 season, and with no more teams in Ontario, the circuit became the New York–Penn League in 1957.

They were joined by the Hamilton Redbirds in 1987 and the Welland Pirates in 1989, but all three clubs had moved back to the United States by 2000.

The book's depiction of players' financial struggles[3] is widely credited with inspiring changes to long-standing minor league compensation structures.

[4][5] On December 9, 2020, Major League Baseball (MLB) announced its list of 120 teams invited to be a part of the minors after restructuring for the 2021 season.

The Mahoning Valley Scrappers, State College Spikes, West Virginia Black Bears, and Williamsport Crosscutters moved to the new MLB Draft League for players wishing to showcase themselves to MLB teams in advance of the annual draft.