In 1917, American Electric Power built the first big mine-mouth power plant, Windsor Plant, at the Windsor Coal Mine in West Virginia. And AEP built the first long-distance transmission line to take power from the Windsor plant to Canton, Ohio, 55 miles away. Since then, AEP has checked off dozens of “firsts” in transmission technology development. In 1947, the first testing of extra-high voltage (500 kV) transmission lines took place at AEP’s Tidd Project in Ohio. In 1958, the first 345-kV interconnection linked the AEP System and Commonwealth Edison. And in 1969, AEP energized the world’s first 765-kV transmission line between Ohio and Kentucky. The 765-kV technology is still the highest voltage used in the U.S. As a technology leader, AEP also has become a transmission policy leader, playing an active role in shaping the national dialogue on transmission siting, planning and development.