From Ohio History Central
On August 14, 2003, the largest power outage in United States history occurred. The blackout affected eight states in the Midwest and Northeastern United States, as well as two Canadian provinces. The blackout resulted from an inadequate supply of electricity to meet the high demands of consumers. The power outage began in Ohio, causing cities in the northern and eastern portion of the state to lose electricity. FirstEnergy, a power company, failed to generate enough electricity to meet demand, causing power plants, 265 total, to fail. Approximately fifty million people lost power. The blackout, according to most estimates, cost businesses nearly six billion dollars. The various electric companies had power restored by the next day.