The First World War was a global conflict that began on 28 July 1914 and ended on 11 November 1918. It took the lives of over 70 million people and left the world in a state of utter chaos. The conflict involved the United States, the United Kingdom, Germany, and Russia. Despite the immense devastation caused by the war, the human spirit remained unbroken.
The war had many causes. The first was the German invasion of Belgium and France. These two countries had remained neutral for nearly a century and hoped to avoid a two-front war with Russia. However, the Allied powers had the advantage of a stronger military and better access to neutral countries such as the United States and the oceans.
The Soviet Union joined the war on June 22, 1941. After the winter war of 1939-1940, Finland also joined the Axis, seeking revenge on Germany for its defeat in the conflict. By October, German troops had reached the Soviet Union. They occupied the Baltic states and captured Smolensk. They fought through the rest of the Soviet Union until they reached the mouth of the Don River, where they were faced with a stiff Red Army resistance.
The United States fought on the side of the Allies in the Pacific and Europe. Germany sank four U.S. merchant ships, including the Lusitania, which carried hundreds of Americans. After the sinking of the Lusitania, Congress passed a $250 million arms bill in 1917 to prepare for the war. The Germans went on to sink four more U.S. merchant ships, which led Woodrow Wilson to declare war on Germany.