Indian Wars is the name used in the united States to describe a series of conflicts, in the 1800s, between the federal government and the native people of North America.
Answer:
Sinking of American merchant ships
Explanation:
In early 1917 Berlin forced the issue. Its declared decision on 31 January 1917 to target neutral shipping in a designated war-zone became the immediate cause of the entry of the United States into the war. Five American merchant ships went down in March.
