4. American naval squadron begins operations in European waters.
The French capture Craonne, near Rheims.
12. The British and French announce captures, in operations since April 9, of a total of 49,579 men, 444 field guns, and 943 machine guns.
14. The Italians begin an offensive from Tolmino to the sea, advancing their lines east of Gorizia and on the Carso.
15. General Pétain succeeds General Nivelle as commander-in-chief of the French armies, with General Foch as chief of staff.
16. The British capture Bullecourt.
18. Selective Service act passed by Congress.
24. The Italians capture important positions near Jamiano. taking 10,009 prisoners.
30. The armed American steamer "Silver Shell" destroys an enemy submarine in the Mediterranean.