Woodrow Wilson was the president during World War I. The war started in 1914. Many countries in Europe and other places fought each other during World War I. Woodrow Wilson and others in the United States did not want to enter World War I. But in 1917, German submarines attacked American ships. Woodrow Wilson decided the United States had to fight in the war. Congress agreed and declared war. Woodrow Wilson was the president during World War I.