Name One War Fought by the United States in the 1900s

United States war, 1900s
The United States fought in World War I and World War II in the 20th century.

To pass the US citizenship test, you will have to answer 10 of a possible 100 questions. The following question is from the USCIS test.

Name one war fought by the United States in the 1900s.

Acceptable Answers:

  • World War I
  • World War II
  • Korean War
  • Vietnam War
  • (Persian) Gulf War


The following is a full explanation of the USCIS question:

World War I

Following a relatively peaceful few decades in Europe, the First World War came as a huge shock to the European people, who had imagined a peaceful and civilized future, not one in which new technology would be used in such a brutal fashion. Even after the war had started and the death toll was high, the expectation was that conflict would be over quickly and not drag on for years leaving millions dead.

While the Second World War is seen in heroic terms, the First World War is, more often than not, viewed as a tragedy from start to finish. The horrors of trench warfare and poison gas were beyond people’s imaginations.

WWII is widely perceived as a fight between good and evil and often cited in condemnation of fascism. However, World War I is used to condemn war itself.

Origins of WWI and Reasons for United States Involvement

In the 1910s, the major European powers had large armies, were divided into various alliances, and on a permanent war footing. All that was missing to garner support for conflict was an event impactful enough to shock the public at large. The assassination of the future Archduke of the Austro-Hungarian Empire and his wife was such an event, and brought war to the continent of Europe once again.

Initially, the United States was neutral and even sold weapons and lent money to Germany, the Austro-Hungarian Empire, and the Ottoman Empire. Although, most loans went to Britain, France, and their allies.

America remained neutral even after many United States citizens were killed as a result of German submarine attacks on merchant ships. When Germany refused to abandon its policy of unrestricted submarine warfare, and the United States intercepted a coded message in which Germany attempted to entice Mexico into attacking the United States, public opinion turned firmly against the Germans, and the United States entered the war.

The War, Outcome, and Aftermath

Victory seemed within Germany’s grasp before the entry of the United States into the war. Unrestricted submarine warfare had taken its toll on Britain and Russia had surrendered to Germany.

Prior the America’s declaration of war on Germany, the Germans engaged in a massive final spring offensive in 1918, but the Allies held their ground, and with the subsequent American support Germany was eventually forced to surrender.

American casualties in World War I (116,000 deaths) were much less than in either World War II or the Civil War.

World War II

During the inter-war years, the American public were of the mind that the United States should not become embroiled in international conflicts that did not threaten them directly. Many Americans were also anti-imperialists who sought to avoid involvement in the Second World War, even after the fall of France.

The Japanese attack on Pearl Harbor changed all that, and Americans came to view the war with Japan as part of a global conflict that included the European war.

While Japan enjoyed much success during the early part of the war, it lagged behind the United States in terms of production capacity. The Japanese strategy was to inflict some defeats on the Americans, gain a strong foothold in much of East Asia, and make the price of victory too high for the Americans to pay.

Even late on in the war, Japan hoped that the Americans would tire of their significant losses and negotiate a favorable peace deal.

A Massive American War Machine

The United States spent ten times as much money on World War Two as it did on World War One. American industries had the power to produce an enormous number of ships, planes, and tanks per annum, and the Axis powers simply could not match this. President Roosevelt was determined to win a conclusive victory against Nazi Germany and Japan.

After the Japanese defeat by the United States Navy at Midway, it became unrealistic for the Japanese Empire to expand further. Germany also suffered heavy losses in Russia. The Axis powers were beginning to weaken, and Germany was unable to invade Britain or defeat the British Air Force.

D-Day

In 1944, a massive Allied Invasion Force landed on the beaches at Normandy. While casualties were high in some areas, the American, British, and other soldiers successfully stormed the beaches, with the German army misled about where the attack would take place.

Hitler did not immediately launch a massive counter-attack, as he believed the D-Day invasion was a ruse and the real invasion force would land elsewhere. Before long, the Allies had 850,000 troops in France and they rapidly became too strong to stop.

The Defeat of the Axis Powers

While the Axis powers briefly pushed the Allies back at the Battle of the Bulge, their fate had been sealed. Germany was invaded, Berlin was occupied, Hitler committed suicide, and Germany surrendered unconditionally a week later.

The Japanese Empire continued fighting for a time, but their resources were becoming increasingly limited. The war ended shortly after the United States dropped two shockingly powerful atomic bombs on Japan, convincing their leaders to surrender.

The discovery of the Holocaust changed how people saw the world. Ideas like eugenics that had been popular in the United States before the war became unpopular and unacceptable. The war led to the creation of the United Nations, whose primary purpose is to maintain international peace and security.

The Korean War

While the First World War was a victory for Russia’s allies, it was a defeat for Russia. The loss led to the Russian Civil War and the creation of the Soviet Union. Following the defeat of fascism in 1945, Americans learned to fear communism.

After World War 2, wars had to be fought more carefully due to the risk of a catastrophic nuclear war. During the Cold War, the United States and the Soviet Union avoided direct conflict, but engaged in numerous proxy wars.

The Korean War involved communist North Korea invading South Korea. The United States eventually faced a sizeable Chinese force in addition to the North Korean army. Since the Soviet Union at the time had few atomic bombs, there were fears that the United States would once again use these weapons.

Why Did the United States Withdraw?

The war did not end quickly in favor of the United States, and it seemed likely that it would escalate if they did not withdraw.

There was also the fear that the Soviet Union would enter the war. Since both sides were using a certain degree of restraint, the war turned into a stalemate. Eventually, the fighting stopped, and Korea split into two countries, one of which is still hostile to the United States.

The Vietnam War

The Vietnam War was more of a defeat than a stalemate for the United States. While many people supported the Vietnam War until its conclusion, it was very unpopular with the public, who saw it as imperialistic rather than defensive. The Vietnam War has a reputation for leading to more trauma for soldiers than most other wars.

Vietnam, which France ruled from the late 19th century to the middle 20th, and was under Japanese rule during World War Two, became an independent state in the 1950s. While the country had initially been anti-communist, a communist insurgency started in the 1950s and quickly gained momentum. It eventually escalated into a war between the communist North and South Vietnam.

America subscribed to the domino theory, which suggested that if you let a country fall to communism, neighbouring countries would follow, so the conflict in Vietnam was part of a broader war against communism.

The war was a protracted one. While American forces never lost a significant battle to the Vietnamese forces, public support turned farther against it.

The Gulf War

The 1991 Gulf War was a success for the United States. When Saddam Hussein invaded Kuwait to capture oil fields to pay off debt accumulated during the Iran-Iraq war, the United States and many Persian Gulf Countries strongly retaliated.

While the war did not remove Saddam from power, it was still a victory for the United States. Iraq’s invasion force was defeated, Kuwait was liberated, and the Iraqi military was greatly weakened. While at least tens of thousands of Iraqis were killed, the war was not nearly as destructive as the Vietnam War or the second Iraq War.