What effect did the British blockade of the Atlantic coast have on the war?

Britain began a naval blockade of Germany. This strategy proved effective, cutting off vital military and civilian supplies and helping the Allies to eventually win the war.

Explanation:

Answer

C) set the US-Canada border at the forty-ninth parallel.

A provision of the Treaty of 1818 that expanded the United States also set the US-Canada border at the forty-ninth parallel.