The beginning of this volume (Janjary 27, 1916) finds President Wilson in New York to inaugurate a speaking campaign on behalf of preparedness that carries him deep into the Middle West, where opposition to the administration's program is said to be strongest. It also finds Colonel Edward M. House, Wilson's confidant in Europe on his second peace mission. House concludes an agreement with Sir Edward Grey, the British Foreign Secretary, for Anglo-American cooperation in a peace plan. Meanwhile, German-American relations reach a new crisis when a submarine torpedoes an unarmed Channel packet, Sussex, on March 24, 1916. Wilson sends an ultimatum to Berlin, warning that the United States will break diplomatic relations with Germany unless she abandons her unrestricted submarine campaign against all merchant shipping. Relations with Mexico, which have been unusually friendly since Wilson's de facto recognition of the government of Venustiano Carranza in October 1915, become heated again. There is a bloody clash between American and Mexican troops at Parral on April 12, and a potentially deadly crisis in Mexican-American relations is developing as this volume ends.