The horrors of World War I were unlike any war up until that point. Trench warfare reshaped the face of battle and took the lives of millions of young men in Europe and around the world. When the war finally came to an end in 1918, there was absolute jubilation.
Below is an image showing the scene on Wall Street on December 5th, 1918 after Germany surrendered.

Source: Library of Congress
Make sure you click on the above image to see some incredible details in a larger version.