It was 1968, and the United States was deeply involved in the Vietnam War. It wasn’t going well, and the westernmost marine base at Khe Sanh was surrounded by three North Vietnamese divisions.

It was then that General William Westmoreland launched Operation Niagara, a joint Air Force, Navy and Marine air campaign. For the next two months, 24,000 fighter jet and 2,700 B-52 bomber flights ran continuous bombing runs.

Why was it called Operation Niagara? Westmoreland compared the mission to the continuously cascading water of Niagara Falls. In this case, the mission called for a continuous cascade of shells and bombs. The plan called for the collection of intelligence to pinpoint the targets, then using everything they had to destroy those targets. It worked.

The Vietnam War’s Operation Niagara was launched on this date in 1968.