President Woodrow Wilson of the United States proposed the "Fourteen Points" peace plan in January 1918, outlining his vision for a just and lasting peace after World War I.

The Treaty of Versailles, signed on June 28, 1919, officially ended World War I between the Allied Powers and Germany.

The Soviet Union and Nazi Germany signed the Molotov-Ribbentrop Pact in August 1939, agreeing to divide Eastern Europe between them.

The Munich Conference was held in September 1938 to discuss the Sudetenland crisis, a territorial dispute between Germany and Czechoslovakia.

The Axis Powers during World War II consisted of Germany, Italy, and Japan.

Operation Overlord was the Allied Powers' strategy for defeating Germany in World War II, involving the invasion of Normandy in June 1944.

The Tehran Conference was held in November 1943 to discuss the Allied Powers' strategy for defeating Germany.

The Yalta Conference was held in February 1945 to discuss the postwar order, including the division of Germany and the creation of the United Nations.

The Potsdam Conference was held in July 1945 to discuss the postwar order, including the division of Germany and the establishment of the Nuremberg Trials.

The Treaty of San Francisco, signed on September 8, 1951, formally ended World War II between the Allied Powers and Japan.

The United States was the first country to drop an atomic bomb during World War II, with the bombings of Hiroshima and Nagasaki in August 1945.

The United Nations was established after World War II to promote peace and cooperation among nations.

The United States was the first country to join the United Nations.

There were 51 countries that were members of the United Nations when it was first established.

Trygve Lie was the first Secretary-General of the United Nations.