Why did the US contribute to World War 1?

The United States contributed to World War I primarily due to unrestricted submarine warfare by Germany, which threatened American lives and commerce, exemplified by the sinking of the Lusitania. Additionally, the interception of the Zimmermann Telegram, in which Germany proposed a military alliance with Mexico against the U.S., heightened tensions. Economic ties with the Allies, particularly through loans and trade, also motivated U.S. involvement, as a victory for the Allies was seen as crucial for American economic interests. Ultimately, these factors led President Woodrow Wilson to seek a declaration of war against Germany in April 1917.