Struggles for power among European empires caused a World War. EQ: What were the causes of WW1? EQ: What methods of fights did the Allied and Central Powers use? EQ: Why did the United States enter WWI? SS5H4a

Causes of the War  In the early 1900s nationalism was leading European countries to war.  Countries such as Germany, Russia, and France competed for land and power. To protect their empires, the nations started build up their armies which is called militarism. They also began to form alliances.

The War Begins  The two most important alliances were the Allied powers, or Allies, and the Central Powers. In 1914, Austria-Hungary, one of the central powers, declared war on Serbia. Serbia had an alliance with Russia, so Russia fought on Serbia’s side. Then, Germany, also a Central Power invaded Belgium and France. France was allied with Russia. World War I had begun.

Allied and Central Powers The Allied Powers Russia France Italy Great Britain Romania Serbia Portugal The Central Powers Germany Austria- Hungary Bulgaria The Ottoman Empire

The Battlefield  When the war began many people were eager for war.  Because of strong Nationalism in Europe, thousands of young men signed up to serve in the military.  Soldiers on both sides fought in long narrow ditches called trenches.  This was called trench warfare.

The Battlefield Millions of Soldiers were killed in these battles. The fighting lasted for 4 years.  With trench warfare soldiers lived in the trenches day and night.  The mud, cold weather and rats made life hard.

America Enters the War When WWI started in 1914 most Americans wanted to stay out of it.  In 1915 a German submarine sank the Lusitania. It was a British passenger ship with many Americans on Board. People were shocked and angry.  The United States entered World War I in 1917 on the side of the Allies.

New Weapons Machine Guns Hand Grenades Tanks Submarines Airplanes

Show What You Know Time EQ: What were the causes of WW1? EQ: Why did the United States enter WWI? Bonus: What methods of fights did the Allied and Central Powers use? SS5H4a