Major Events

One key event that started World War I was the assassination of the archduke of Austria and his wife. This started a war between Austria and Serbia. Serbia wanted to work out the situation through international diplomacy, but Austria-Hungary, who was outside of diplomatic relations, ordered the mobilization of troops.

Germany sent out an ultimatum telling Russia to halt mobilization of their troops, and they also told France to become neutral if war started between Russian and Germany. France ignored the demands, so the next day Germany sent troops into Belgium and declared war against France. Great Britain then declared war against Germany because they were allies with Belgium.

Initially, President Woodrow Wilson wanted Americans to remain neutral. However, by 1917, when Germany had invaded Belgium and then had sunk a ship with 100 Americans on board, Woodrow Wilson asked Congress to declare war on Germany on April 6, 1917. The U.S. troops aided the French, helping them counter attack German forces who surrendered. This led to a peace conference in Paris, France on November 11, 1918.