World War I broke out in 1914 after Austria declared war on Serbia. The US initially declared neutrality but became drawn into the war after several events, including German U-boats sinking American ships like the Lusitania in 1915, killing over 100 US citizens. Germany agreed to the Sussex Pledge in 1916 to warn ships before attacking but broke the pledge in 1917. Additionally, the Zimmerman Telegram was intercepted in 1917 where Germany tried to enlist Mexico to attack the US. Due to these events weakening its neutrality, the US declared war on Germany and its allies in April 1917.

1. THE US IS DRAWN INTO WORLD WAR I

2. 1914-WORLD WAR
BREAKS OUT
• JULY 28, 1914 AUSTRIA DECLARES
WAR ON SERBIA SPARKING WORLD
WAR I.
• THE US DECLARES NEUTRALITY
AND VOWS TO NOT GET INVOLVED.

3. 1915-GERMAN U-
BOAT SINKS THE
LUSITANIA
• US SHIPS WERE GETTING ATTACKED
BY GERMAN SUBMARINES (U-
BOATS)
• PASSENGER LINER LUSITANIA IS
SUNK KILLING 128 AMERICANS

4. THE SUSSEX PLEDGE
• 1916-GERMAN U-BOATS SINK
A FRENCH SHIP THE SUSSEX.
AMERICANS WERE INJURED.
GERMANY FEARED US
INVOLVEMENT IN THE WAR AND
AGREED TO SIGN THE SUSSEX
PLEDGE: IN THIS GERMANY
AGREED TO WARN SHIPS TO
EITHER TURN AROUND OR BE
TORPEDOED.
• FEBRUARY 1, 1917: GERMANY
BREAKS THE PLEDGE

5. ZIMMERMAN TELEGRAM
• MARCH 1ST BRITAIN INTERCEPTED
A TELEGRAM SENT BY GERMANY TO
MEXICO. IN THE ZIMMERMAN
TELEGRAM GERMANY ATTEMPTED
TO GET MEXICO TO ATTACK THE
US AND JOIN THE CENTRAL
POWERS.
• MARCH: FOUR US MERCHANT
SHIPS SUNK BY GERMAN U-BOATS.
• APRIL—THE US DECLARED
WAR ON GERMANY AND HER
ALLIES.

6. ATTRIBUTIONS
• SLIDE 1: BY NATIONAAL ARCHIEF - HTTPS://WWW.FLICKR.COM/PHOTOS/NATIONAALARCHIEF/2941024033/, NO
RESTRICTIONS, HTTPS://COMMONS.WIKIMEDIA.ORG/W/INDEX.PHP?CURID=53561070
• SLIDE 2: NEW-YORK TRIBUNE. (NEW YORK [N.Y.]), 29 JUNE 1914. CHRONICLING AMERICA: HISTORIC AMERICAN
NEWSPAPERS. LIB. OF CONGRESS. HTTP://CHRONICLINGAMERICA.LOC.GOV/LCCN/SN83030214/1914-06-29/ED-
1/SEQ-1/
• SLIDE 3: BY BRITISH GOVERNMENT [PUBLIC DOMAIN], VIA WIKIMEDIA COMMONS
• SLIDE 4: PUBLIC DOMAIN:
HTTPS://COMMONS.WIKIMEDIA.ORG/WIKI/CATEGORY:WOODROW_WILSON#/MEDIA/FILE:LOS_ANGELES_HERALD,_
NUMBER_100,_26_FEBRUARY_1917_(PAGE_1_CROP).JPG
• SLIDE 5:
• POLITICAL CARTOON: PUBLIC DOMAIN HTTPS://COMMONS.WIKIMEDIA.ORG/WIKI/FILE:SOME_PROMISE.JPG
• NEWSPAPER: PUBLIC DOMAIN:
HTTPS://COMMONS.WIKIMEDIA.ORG/WIKI/CATEGORY:UNITED_STATES_IN_WORLD_WAR_I#/MEDIA/FILE:%22HOUSTON_PO
ST%22_(APRIL_3,_1917).JPEG