Legislation splitting off Bronx County from New York County was enacted in 1912 with an effective date of January 1, 1914. Prior to 1874 the entire area had been part of Westchester County. See McCarthy, Thomas C. A 5-Borough Centennial Preface for the Katharine Bement Davis Mini-History. New York City Department of Corrections. [2008-01-25]. （原始内容存档于2012-07-09）.
Legislation splitting off Bronx County from New York County was enacted in 1912 with an effective date of January 1, 1914. Prior to 1874 the entire area had been part of Westchester County. See McCarthy, Thomas C. A 5-Borough Centennial Preface for the Katharine Bement Davis Mini-History. New York City Department of Corrections. [2008-01-25]. （原始内容存档于2012-07-09）.
