During World War I (1914-1918) Mexico remained neutral. During this time, Mexico was preoccupied with its revolution (1910-1920) which took place the same time as World War I. In January 1917, British agents intercepted a telegram sent to German Ambassador to Mexico Heinrich von Eckardt by Arthur Zimmermann, State Secretary for Foreign Affairs of the German Empire. In the telegram, Germany proposed to Mexico that if the United States were to join the war, Mexico should join and side with the Central Powers. In appreciation, and if the Central Powers were to win, Mexico would recuperate the territory of Texas, New Mexico and Arizona that Mexico lost in its war with the United States during the Mexican–American War in 1848. The telegram, known as the Zimmermann Telegram was intercepted when the telegram was being wired to the German embassy in Washington, DC to be re-routed to Mexico City. Mexico eventually rejected the telegram and continued to remain neutral during the war.