Key events in Truman's presidency were the establishment of the Marshal plan which had a goal of helping European countries rebuild so as to prevent them from falling to communist influence from the Soviet Union and China. He was also one of the founders of the United Nations and was known for being the only president ever to use nuclear weapons in war, on Hiroshima and Nagasaki.
Eisenhower was known for the ideas of the space race against the Soviet Union, as well as for increasing the power of the CIA in order to prevent poor countries from becoming communist ones. Like Truman, he believed that it's necessary to prevent the spread of communism which is why he had military actions in Africa and Asia, as well as the middle east.
Kennedy was known for the war in Vietnam and the failed invasion of Cuba. He too continued the policies of containment however they started losing popularity and Kennedy was criticized for participating in the Vietnam war. He also led the bay of pigs campaign in Cuba which proved to be a failure after they failed to remove Castro from his position. He was also active in negotiations with Latin American countries.
Lyndon B. Johson was mostly known for Vietnam. Even when it seemed that the United States might leave the war, he kept them the people in it and even increased the amount of soldiers because he believed that the region needed to be stabilized. He also supported Israel in the six-day war which was difficult since the Arabs were supported by Soviets.
Nixon was known for reopening negotiations with China and reducing tension with the Soviet union through the nuclear programs which were supposed to reduce the amounts of weaponry. He also withdrew the troops from Vietnam and ended the United States participation in the war. Although he tried helpin Chile in establishing a democratic liberal rule, he was unsuccessful and a totalitarian regime was introduced.
