Final answer:
In the context of the ships formed near the mouth of the Mississippi River, the term 'blockade' refers to a military tactic used to restrict or prevent the movement of ships.
Step-by-step explanation:
In the context of the ships formed near the mouth of the Mississippi River, the term 'blockade' refers to a military tactic. A blockade involves the use of naval forces to restrict or prevent the movement of ships into or out of a specific area. This can be done to cut off supplies, prevent reinforcements, or exert control over a certain region. For example, during the American Civil War, the Union navy implemented a blockade of Confederate ports to weaken their ability to trade and receive supplies.