PJM Interconnection is a regional transmission organization (RTO) that coordinates the movement of wholesale electricity in parts of the United States, including all or parts of 13 states and the District of Columbia. They ensure the reliability of the electric grid and operate a competitive wholesale electricity market. Founded in 1927, PJM has evolved to manage one of the world's largest power grids and electricity markets, balancing supply and demand in real-time while facilitating long-term grid planning and innovation in energy technology.