Exelon Corp. operates as a utility services holding company, which engages in the energy generation, power marketing, and energy delivery business. The company operates through the following segments: Mid Atlantic, Midwest, New England, New York, Electric Reliability Council of Texas (ERCOT) and other Power Regions. The Mid-Atlantic segment represents operations in the eastern half of PJM, which includes New Jersey, Maryland, Virginia, West Virginia, Delaware, the District of Columbia and parts of Pennsylvania and North Carolina. The Midwest segment represents operations in the western half of PJM, which includes portions of Illinois, Pennsylvania, Indiana, Ohio, Michigan, Kentucky and Tennessee, and the United States footprint of MISO, excluding MISO's Southern Region, which covers all or most of North Dakota, South Dakota, Nebraska, Minnesota, Iowa, Wisconsin, the remaining parts of Illinois, Indiana, Michigan and Ohio not covered by PJM, and parts of Montana, Missouri and Kentucky. The New England (NE) segment represents the operations within (International Standards Organization) ISO-NE covering the states of Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island and Vermont. The New York (NY) segment represents operations within ISO-NY, which covers the state of New York in its entirety. The ERCOT segment represents operations within Electric Reliability Council of Texas, covering most of the state of Texas. Exelon was founded in February 1999 and is headquartered in Chicago, IL.