The soviet union held its first successful atomic test on august 29, 1949. what impact did this have on the united states?

The United States of America was in utter shock. They had not anticipated that the Soviets would be so quick to make their own atomic bomb so quickly.

Explanation:

After the successful tests of the Soviets, America felt threatened about Soviets having the secrets of a nuclear weapon.

America wanted to be on top of the game. They quickly started to make hydrogen bombs. Which were far more lethal than the nuclear ones. Soon many other countries followed suit.  

The correct answer is  A) It fed the American public's fears about the dangers of communism.

The other options of the question were B) It spurred Congress to increase Marshall Plan aid to Western Europe. C) It prompted the formation of the North Atlantic Treaty Organization. D) It convinced the Truman administration to pursue a policy of containment.

The Soviet Union held its first successful atomic test on august 29, 1949. The impact that this had on the United States was "It fed the American public's fears about the dangers of Communism."

And of course, this created more tension between the USSR and the US. During the Cold War years after World War II, the USSR tried to spread Communism all over the world. However, the United States tried to stop it through the foreign policy of containment. The arms race, the producing nuclear weapons created moments of tension as the Cuban Missiles Crisis of 1962, when the world was at the brink of another world war.