This is a list of some of the ways regions is defined in the United States. Many regions are defined in law or regulations by the federal government; others by shared culture and history, and others by economic factors.
Interstate regions
Census Bureau-designated regions and divisions
U.S. Census Bureau Regions and Divisions.
Since 1950, the United States Census Bureau defines four statistical regions, with nine divisions.[1][2] The Census Bureau region definition is "widely used ... for data collection and analysis",[3] and is the most commonly used classification system.[4][5][6][7]
Puerto Rico and other US territories are not part of any census region or census division.[9]
Federal Reserve Banks
Federal Reserve districts.
The Federal Reserve Act of 1913 divided the country into twelve districts with a central Federal Reserve Bank in each district. These twelve Federal Reserve Banks together form a major part of the Federal Reserve System, the central banking system of the United States. Missouri is the only U.S. state to have two Federal Reserve locations within its borders, but several other states are also divided between more than one district.
^"The National Energy Modeling System: An Overview 2003" (Report #: DOE/EIA-0581, October 2009). United States Department of Energy, Energy Information Administration.
^"Perhaps the most widely used regional classification system is one developed by the U.S. Census Bureau." Dale M. Lewison, Retailing, Prentice Hall (1997): p. 384. ISBN978-0-13-461427-4
