Involvement in World War I had a striking impact on the United States. Domestically, the United States enacted a number of different programs to aid the military in achieving its objectives. Some of these initiatives deprived Americans of certain personal liberties. For example, the Espionage and Sedition Acts made it illegal to speak out against the war, government, or public officials and allowed the government to censor political opposition. This included spying on citizens and inspecting people's mail. This would set a precedent for former wars and other times of crises.
Various laws were enacted that mobilized the economy and hampered free market capitalism. These laws mandated businesses to follow certain labor, wage, and price policies set by the government. During the war, the United States operated as a command economy. This continued a trend of government interference in the economy that began during the Progressive era and would reach a pinnacle during the New Deal years.
The United States also organized a government sanctioned campaign of propaganda that was unprecedented in American history. Speaking tours, movies, music, and propaganda posters all touted the importance of the war. The majority of Americans bought into this propaganda campaign, as evidenced by the billions of dollars in war bonds purchased during the war.
Internationally, the United States entered the war at a perfect time. Having decreed neutrality from the beginning of the conflict, but funding the Allied powers, the United States had an economic stake in the war. With the victory on the side of the Allies, Woodrow Wilson played an important part in the peace process. While Congress was interested in a policy of isolation after the war, Wilson's Fourteen Points had an important impact on world affairs. As an example, the League of Nations was established to prevent future global conflicts. While the League of Nations was a failure, it successor the United Nations has endured for almost seventy years.
The war also had the effect of thrusting the United States on the international stage as an industrial-military power. Despite the best efforts of Congress to isolate the United States from the conflicts of Europe after the War, the die had been cast for the country to be a world super power.