"The Vanguard launch came after the success of Sputnik 1 and Sputnik 2, which was a one-two propaganda punch by the Soviets that was of great concern to the United States' leadership—and to many ...

The Vanguard rocket program ... Just two months earlier, the Soviet Union stunned the world by launching Sputnik 1, the first artificial satellite. The success ignited panic in the United States ...

Vanguard 1 is neither the world's first artificial satellite (Sputnik 1) nor the first artificial satellite of the United States (Explorer 1), but it holds a title that will be remembered in history.