WWI was the sixth deadliest conflict in world history.
WWI transformed the U.S. into the largest military power in the world.
WWI allied soldiers would fire thousands of rounds at random over the German trenches to boil the water in their machine guns to make tea.
The youngest soldier to serve during WWI was only 8 years old.
The WWI ended at 11 o'clock in the morning of the 11th day of the 11th month of 1918.
The Spanish flu caused about a third of total military deaths in WWI.
The room of a WWI French soldier is still untouched since 1918.
The last surviving WWI Veteran was a woman. She was a waitress at an air base.
Teddy Roosevelt volunteered for service in World War I ten years after having served as U.S. president.
Spain was neutral in WWI and WWII, but experienced a civil war (1936-1939) which killed over 500,000 people.