If the United States declared war on Germany, Mexico would recapture the territories it lost to the United States in the Mexican-American War (1846–1848). The British intercepted and decoded the telegram and shared it with the United States government.
Publication of the telegram in early March 1917 provoked widespread outrage and anti-German sentiment in the United States. It contributed significantly to the decision of the U.S. government to declare war on Germany on April 6, 1917.