a
person from Serbia. World War I was called the Great War. More than
thirty countries fought the war in Europe, Africa and the Middle
East. The war began on July 28, 1914 when Austria-Hungary's Archduke
Ferdinand and his wife were shot by a
person from Serbia.
There were four main causes of the war. The first cause was nationalism. They wanted it to the bast. The second cause was militarism. Each one wanted the biggest and strongest military. The third cause was imperialism. Every one wanted more colonies and lands that belonged to other countries. The final cause was alliances. They promised to fight for other countries in a war.
There were two main alliances in the war. One was the Allies. It was Great Britain, France, and Russia. The second was the Central Powers made of Germany and Austria-Hungary.
Some countries were neutral. They didn't fight in
the war. Some neutral
countries were Norway, Sweden, and Spain.
The United States was neutral at the start. They helped the Allies by sending food and weapons. German Americans were treated very badly. They lost their jobs. They stopped teaching German in school.
The United States entered the war in April, 1917. They entered the war because the German submarines sunk our ships. Over 1,000,000 Americans fought in the war. Over 100,000 died.
The Allies won the war on November 11, 1918.
Germany was punished by 
the
Treaty of Versailles. They paid billions of dollars to the Allies.
They lost some of their land and colonies.
The League of Nations was made in 1920. 42 nations joined. It was a group of countries working for world peace. The United States didn't join it because they didn't want to fight in another war.
After the war was over, the countries had
problems. Many people had no jobs, homes, or money. Millions were
killed or wounded. Many countries 
had
no money. The Germans hated the Allies and their
countries.