U-boats, 101;
  see Submarine warfare. 
Ukrainia, 136-137. 
United States,
  danger from Germany, 54-55;
  neutral trade, 100, 102, 131;
  protests against submarining, 103, 116, 129;
  enters the war, 130-133;
  army in France, 145-147, 150, 163;
  in the war, 152-167;
  navy, 152;
  raising an army, 152-153;
  aircraft, 153;
  food control, 154;
  fuel control, 155;
  transportation control, 156;
  shipbuilding, 157;
  seizes German ships, 158;
  paying for the war, 158-159;
  Red Cross, etc., 160;
  rise in prices, 161;
  German propaganda, 165-167;
  peace problems, 168-171.

Venezuela, Germany in, 55. 
Venice, threatened, 128. 
Verdun, battle of, 107-108. 
Victor Emmanuel, 18. 
Vienna, conference of 1815, 7. 
Vimy Ridge, taken, 118.

War, see Great War;
  war as a profitable business, 27. 
War Savings Stamps, 159. 
Wilson, President,
  Lusitania case, 103;
  Sussex case, 116;
  breaks with Germany, 128-129;
  asks for declaration of war, 132;
  fourteen-point address (Jan. 8, 1918), 135, 171-179;
  peace notes of 1918, 150. 
Wounded, care of, 169.

Young Men’s Christian Association, 160. 
Ypres, battle of, 95. 
Yser River, 82.

Zeppelins, 104. 
Zimmerman note, 130.