Final answer:
True, the British navy's blockade of American ports during the Revolutionary War significantly hindered American supply lines and reinforcement efforts.
Step-by-step explanation:
True, a blockade of the American coast by British ships did prevent supplies and reinforcements from reaching the Continental Army. During the 18th and early 19th centuries, the British navy was dominant on the high seas and leveraged this advantage to establish blockades on American ports during the Revolutionary War. The Americans lacked the naval forces necessary to break these blockades and this hindered their ability to obtain vital supplies and support. The blockade, along with actions such as the capturing of American ships and impressment of American sailors, created significant challenges for the American war effort.