British soldier eating his dinner in the trenches during World War I.

1. World War I, 1914–1920 World War I breaks out in Europe, the United States gets involved in the war, and President Wilson attempts to shape the peace. British soldier eating his dinner in the trenches during World War I. NEXT

2. World War I, 1914–1920 SECTION 1 War Breaks Out in Europe SECTION 2 America Joins the Fight SECTION 3 Life on the Home Front SECTION 4 The Legacy of World War I NEXT

3. Section 1 War Breaks Out in Europe After World War I breaks out, the United States eventually joins the Allied side. NEXT

4. SECTION 1 War Breaks Out in Europe Causes of World War I • Assassination of Archduke Franz Ferdinand starts World War I • War has many underlying causes: - imperialism - nationalism - militarism—belief that nations need a large military force - alliances NEXT

5. Serbian nationalist Gavrilo Princip (right) seized by police after fatally shooting Austrian Archduke Franz Ferdinand and his wife on June 28, 1914.

6. Archduke Franz Ferdinand

7. SECTION 1 continuedCauses of World War I • European nations are divided into two opposing alliances: - Central Powers—Austria-Hungary, Germany, Ottoman Empire, Bulgaria - Allies—Serbia, Russia, France, Great Britain, Italy, 7 other countries Interactive NEXT

8. SECTION 1 Stalemate in the Trenches • German army invades Belgium, advances into France (1914) • French, British troops stop German advance, 1st Battle of the Marne • Fight for 3 years in trenches stretches across France, neither side wins • Trench warfare—troops fight in trenches, use artillery, machine guns • Area between opposing trenches called “no man’s land” • Battle of Somme, 1.2 million casualties, Allies gain about 7 miles NEXT

9. Soldiers in trenches.

17. The Lancashire Fusiliers fix bayonets as they prepare to go "over the top" in the Battle of the Somme, July 1916.

18. Note on the chart how each of the following causes led to World War I Europeans wanted to prove the superiority of their nations; also, certain ethnic groups were willing to fight to form their own separate nations. Europeans had built up their military forces before the war. Conflicts between two nations drew their allies into a larger war. European nations competed for colonies. Germany resented having fewer colonies than other nations and wanted to gain more. touched off war by giving Austria-Hungary a reason to fight Serbia.

19. SECTION 1 A War of New Technology • New technology raises death toll • Tanks, British invention, smashes barbed wire, crosses trenches • Machine guns fire 600 bullets a minute, poison gas burns, blinds • WWI 1st major conflict that uses fighter airplanes • U-boats—submarines used by Germans to block trade NEXT

20. British motorized machine gun battery near the Somme

21. Water cooled German Maxim machine gun. Same rpm as Vickers. This weapon accounted for 90% of the British casualties on the opening day of the Somme Offensive, 1-Jul-1916.

23. British Invention Crossed trenches Reason= combat machine guns 1st used at the Battle of the Somme Tanks

25. French Schneider

26. Canadians get a lift on a British Mark IV. They wont get where they're going fast - this tank's top speed was 4 mph.

33. 1st used in combat during WWI Mainly observation Some air to air combat Dropped bombs late in the war but had little impact Airplanes

36. German U-boat (1917).

37. SECTION 1 America’s Path to War • U.S. President Woodrow Wilsonannounces policy of neutrality • neutrality—refusing to take sides in a war • Britain sets up naval blockade of German ports • U-boat sinks British passenger ship Lusitania, kills 1,198 total, 128 Americans • Wilson demands that Germany stop unrestricted submarine warfare • Germany at first agrees, Wilson wins reelection • Germany resumes submarine warfare, January 1917 Continued . . . NEXT

39. New York Times headline about the German sinking of the British ocean liner Lusitania on May 7, 1915.

43. SECTION 1 continuedAmerica’s Path to War • British intercept Zimmermann telegram: - sent by German foreign minister Arthur Zimmermann - proposes that Mexico join the Germans - Germany will help Mexico get back “lost” territories in U.S. • U.S. furious about telegram, U-boats sink 3 U.S. ships • President Wilson asks for declaration of war, Congress votes for war NEXT

44. Describe the new style ofwarfare and the new weapons that made World War I different from earlier wars. Tanks smashed obstacles and protected soldiers inside; machine guns fired 600 bullets a minute; poison gas burned and blinded soldiers; fighter planes shot from the air; submarines sank ships. Soldiers fought from protected ditches, suffered many casualties, and gained little ground.

45. SECTION 1 Revolution in Russia • Russian army is outfought by smaller German army (1915) • Food shortages, inflation lead to strikes by angry Russian workers • Czar Nicholas II of Russia steps down (1917) • Communists led by Vladimir Lenin overthrow temporary government • Lenin makes peace with Germany (1918) • German troops turn from Russia to the Western front Communist revolutionaries unfurl a Red Flag in Moscow (1918). NEXT

46. Bolsheviks (part of the Communist Party) take control Vladimir Lenin-- Leader Did not support the war Russian Revolution

47. Vladimir Lenin

49. Russians made peace with the Central Powers and withdrew from war Treaty of Brest- Litovsk

50. Make a time line showing four events that led the United States to declare war on Germany. Start with May 1915.