World War I: World War I was a global conflict fought from 1914 to 1918, involving many countries including the United States.
Russian Revolution: The Russian Revolution refers to the series of events in Russia that led to the overthrow of the monarchy and the establishment of communist rule in 1917.
Zimmerman Telegram: The Zimmerman Telegram was a secret message sent in 1917 by Germany to Mexico proposing an alliance against the United States during World War I.