The Communists led by Mao Zedong overthrew the Nationalist regime in 1949, ending the Chinese Civil War (part of the international Cold War), and starting Communist rule under Mao. The Japanese had already been defeated and driven from China in 1945 with the end of World War II (the Nationalist-Communist civil war resumed shortly after this). The Qing dynasty, the last imperial Chinese dynasty, had already been overthrown in 1912. The Ming dynasty had immediately preceded it, and had been overthrown in 1644.

The Treaty of Versailles set the terms by which the combatants of World War One would progress in the wake of World War One, and it established very harsh and humiliating conditions for Germany. Germany was forced to pay war reparations and accept full responsibility for the war. By 1924, it had become clear that Germany could not pay off its massive debt, and its attempts to do so were causing hyperinflation. In an attempt to remedy this situation, the Dawes Plan restructured German debt and lent a great deal of money from the U.S. treasury to the German government.

The Kellogg-Briand Pact was signed in 1928 by the United States, France, and Germany. Most of the rest of the major powers in the world followed suit and signed shortly after. The Kellogg-Briand Pact renounced the use of warfare as a means of settling international disputes.

The Palmer Raids can be seen in the larger context of the Red Scare that gripped American society after World War One. The Palmer Raids were designed to forcefully exile foreign citizens living in America who were deemed radical leftists; anarchists and communists were particularly likely to be targeted.

Woodrow Wilson was elected President in 1912 and served from 1913-1921 (World War One lasted from 1914-1918). Wilson initially opposed intervening in the “Great European War,” as most Americans knew it. But, cultural similarities with the British and American public opinion turning against the Germans after the sinking of American passenger ships (such as the Lusitania in 1915) eventually caused the United States to enter the war on the side of the Allied powers in 1917. Wilson is fondly remembered for his attempts to create the first collective political organization designed to represent the interests of the entire world - The League of Nations - although this would subsequently fail as a result of a war-weary American Congress that wanted to remain out of European affairs. 

At the time of the First World War, the four biggest Latin American economies were Mexico, Chile, Brazil, and Argentina. All four countries were, at least in the cities and coastal regions, relatively modernized, and they all engaged in widespread trade with the rest of the world. Brazil, in particular, had many raw and luxury resources to export and Argentina had a consistent surplus of grain, wheat, and meat products. All four of these nations would play an important role in the First World War, either by remaining neutral and supplying the Allies and the Central Powers with supplies (Mexico, Chile, and Argentina) or by declaring war on Germany and hounding their ships in the Atlantic (Brazil).

The primary contribution of Brazil during the First World War came from its contribution of raw and luxury resources to the Allied Powers, particularly when this became exclusive following Brazil's declaration of war in 1917; however, the primary military contribution of Brazil was the support its navy to help the efforts of the Allied Powers to pursue German submarines, which allowed for Allied control of the Atlantic Ocean.

The Zimmerman Telegram was a message from the German high command to the Mexican government, which promised that if Mexico attacked the United States during World War One, then the German government would return Mexican territory in the southwest of the United States in the event of a German victory. The telegram became public knowledge and was one of the main reasons why the United States declared war on Germany in 1917. 

The Sussex Pledge was issued by the German government in 1916. It was issued in response to a statement made by President Woodrow Wilson that the United States would enter the war if Germany did not stop its policy of unrestricted submarine warfare. The Sussex Pledge promised to stop sinking American ships and to allow partial freedom of the seas; however, the German government rescinded the policy in January of 1917, believing that they could win the war by preventing France and England from trading with the United States. This backfired and caused the United States to join the war on the side of the Allied Powers. 

The Supreme Court case, Schenck v. United States (1919), relates to the implementation of the draft during World War One. Specifically, the court ruled that men who were encouraging young men to resist the draft were violating the Espionage Act of 1917 and endangering the safety and security of the nation.