Final answer:
In World War I, the U.S. demanded apologies and restitution from Germany after German submarines attacked a civilian ferry with U.S. citizens. they also laid mines in the North Sea and implemented the convoy system to protect British ships from U-boat attacks.
Step-by-step explanation:
In World War I, the United States took several measures to help British ships avoid being attacked by German submarines. Firstly, President Wilson demanded apologies and restitution from Germany after German submarines torpedoed the Sussex, a civilian ferry, and several U.S. citizens were killed. Germany then agreed to engage in restricted submarine warfare, meaning they would not target U.S. ships and would try not to fire on ships carrying U.S. citizens. Additionally, soldiers in the U.S. navy laid mines in the North Sea to bottle up German U-boats and reduce the U-boat threat.
The Allied Forces also utilized the convoy system, where merchant vessels would travel in large groups with a guard of circling destroyers and cruisers for protection. As a result of these measures, the U.S. was able to significantly minimize the danger to British ships from German submarines.