This timeline paints a picture of this history of the transmission system in the United States.


  • 1882 – The first distribution systems are built in Manhattan and New Jersey. These systems use direct current over copper wiring.
  • 1896 – The first alternating current line is built to connect Niagara Falls to Buffalo, NY.
  • 1907 – Commonwealth Edison become the first to consolidate power companies into one unit.


  • 1914 – By the end of the year, 43 states have regulatory commissions with oversight of electric utilities.
  • 1932 – By the end of the year, eight large holding companies control about three-quarters of the investor-owned utility business. Many of these holding companies cross state lines.
  • 1960 – 1969 – Economies of scale make it cheaper to make electricity. The number of miles of high-voltage transmission lines tripled from 10 years earlier to more than 60,000 circuit miles.


  • 1935 – The first federal regulation of the electric power industry – the Public Utility Holding Company Act (PUHCA) – is signed by President Roosevelt. This act creates a) vertically integrated utilities in monopoly service areas and b) the Federal Power Act that gives Federal Power Commission jurisdiction over transmission. Siting of generation and transmission, and  electrical rates, remains under state control.
  • 1978 – The Public Utility Regulatory Policy Act (PURPA) is passed, mandating utilities to buy power from companies that were not utilities. This spawns non-utility power generators and a need for more access to the transmission system.
  • 1992 – The Energy Policy Act (EPACT) is passed. It mandates that all generators get access to the transmission grid for the same price the utility would charge itself for access to the grid. 
  • 1995 to present – FERC passes several orders to better enforce EPACT:
    • Order 888 implemented open access to the transmission systems owned by public utilities
    • Order 889 implemented the OASIS to provide transmission customers with on-line information about available transmission capacity, prices and other information to implement open access transmission service, and established the FERC Standards of Conduct to functionally separate the transmission and wholesale merchant functions of public utilities.
    • Order 2000 encourages transmission-owning utilities to form Regional Transmission Organizations (RTOs), which are given the task of regional planning, pricing and creating a market for wholesale power.
    • Order 2003 established standard rules for interconnection of generators larger than 20 MW to the transmission system.