Dollar Diplomacy was part of the early period of American imperialism, at the beginning of the Twentieth Century. It was most frequently used under President William Howard Taft. Dollar Diplomacy involved establishing businesses and lending money to investors in foreign countries (particularly Central America) and taking economic, political, and financial control over a country by wielding the power of big business and financial obligation.

The Iran-Contra Affair was a political scandal that occurred during the Reagan administration. It involved the sale of arms to Iran (illegal under an international embargo) and the use of that money to fund rebels in Nicaragua (prohibited by Congress). It was also an attempt to arrange for the release of American hostages in Iran.

The history of Latin America in the twentieth century is a history of revolution, populism, military coup d'etats, and American interference. Argentina is often held as the classic example of these competing trends and movements and Juan Peron is one of the most famous rulers. He came to power following the coup d'etat of 1943, in the elections of 1946, and ruled until 1955 when he himself was overthrown by a separate coup d'etat. 

The Good Neighbor Policy, initiated by Franklin D. Roosevelt in 1933, promised that the United States would adopt a policy of non-interference in the affairs of the politics of Latin American countries. This did not function as promised, however; during the Cold War, the United States intervened in Latin America on numerous occasions. 

In response to growing social unrest and economic difficulties in Latin America in the 1960s, John F. Kennedy initiated the Alliance for Progress to encourage social reform and economic growth.

The English Commonwealth of Nations is a term used to refer to the loose association of former English colonies that exist all over the world. The United States of America is one of the few former English colonies that is not a member, but Canada remains in the English Commonwealth, as do countries like Australia and India.

The beginning of the Great Depression took place during the presidency of Herbert Hoover who, like many Presidents when the economy is in a bad state, was widely blamed for the disaster. Many Americans were forced from their homes and unable to find work and set up slums and shantytowns throughout American cities. In the early 1930s hundreds of thousands of Americans lived in these “Hoovervilles.”

Of these Presidents, Woodrow Wilson, Barack Obama, and Theodore Roosevelt received the Nobel Peace Prize during their terms. Jimmy Carter received his long after his Presidency ended for his dedicated humanitarian work in the years since. Only John F. Kennedy did not receive the Nobel Peace Prize.

The Harlem Renaissance took place in the 1920s. It was an artistic movement, with intellectual and social qualities, that took place among the African-American community of New York City. In particular, it was a time of a dramatic increase in the writings of African Americans about their experiences.

The United States-led coalition invasion of Afghanistan began in October 2001 and only ended recently in December of 2014. The war began in response to the 9/11 terrorist attacks on American soil less than a month earlier. The publicly stated goals of the American forces were to defeat and dismantle Al-Qaeda and to remove the Taliban government from power.