Why did Wilson ask congress for declaration of war against Germany?

President Woodrow Wilson asked Congress for a declaration of war against Germany in April 1917 primarily due to Germany's unrestricted submarine warfare, which threatened American lives and commerce. The sinking of ships like the Lusitania, along with the Zimmerman Telegram that revealed Germany's proposal to Mexico for an alliance against the U.S., heightened tensions. Wilson believed that the U.S. needed to defend democracy and maintain international stability, leading him to conclude that war was necessary for these principles.