John F. Kennedy
He was the president during part of the cold war, the superpower rivalry, and the Cuban missile crisis. He was the president who went on the media (television in particular) and communicated to the people about the crisis. He allowed the leader of the Soviet Union to withdraw their missiles.
Lyndon B. Johnson
He signed the civil rights act of 1964 into law and the voting rights act of 1965. He waged a war against poverty in his agenda. In his attempt to win that war, he set the great society, signed economic opportunity act, set programs like providing food stamps and extended welfare to destitute families. He created a department of housing and urban development.