Week 9: World War I

Watch the Following Supplemental Videos

1. Blockades, U-boats and Sinking of the Lusitania [Enter key starts video]
   Learn about the naval warfare between Britain and Germany that led to the sinking of the Lusitania. Created by Sal Khan.
   
2. Zimmermann Telegram [Enter key starts video]
   An intercepted telegram between Germany and Mexico led the United States to declare war. Created by Sal Khan.
   
3. United States Enters World War I [Enter key starts video]
   Learn about the United States’ reasons for entering World War I. Created by Sal Khan.