至于美国的国内事务，年轻的美国民众对战争感到相当厌烦。妇女正行使刚刚取得的新权利 (1920年得到的投票权) ，而许多白人也开始对非裔美人的文化感到兴趣。哈林区的夜总会越来越热闹，舞台上的聚光灯照耀着许多爵士音乐家，例如路易斯．阿姆斯壮，以及杜克．艾林顿等人。

Foreign affairs (relationships with other countries) took up a great deal of President Woodrow Wilson's attention. In Europe, there was the outbreak of World War I, also known as the Great War, in 1914, and in Mexico, there was the Mexican Revolution. Although at first Americans did not want to get involved, they supported the Allies in their fight against Germany, Austria, Hungary, Bulgaria and Turkey. Finally, the U.S. entered the war in 1917. The war concluded in 1918 and the Treaty of Versailles was signed in 1919. The Allied Powers of the U.S., Great Britain, Japan, Italy, Russia, France, Belgium, Serbia and Montenegro had been victorious.

Back at home, young people were tired of the war. Women exercised their newly found freedom (having won the right to vote in 1920) and many whites took up an interest in African American culture. Harlem nightclubs thrived, spotlighting numerous artists such as jazz musicians Louis Armstrong and Duke Ellington.