First U.S. Hydroelectric Plant: Niagara Falls, Not Hoover Dam

The first hydroelectric power plant in the United States was not built at Hoover Dam. That distinction belongs to the Niagara Falls plant, which began operation in 1882. Hoover Dam's hydroelectric facility came much later, completed in 1936.

Niagara Falls' early adoption of hydroelectric power leveraged its immense water flow and vertical drop, establishing the foundation for large-scale renewable energy in North America. Hoover Dam, while iconic and massive, was a later milestone in the same trajectory.