In the early 19th century, what type of Navy vessels were primarily used to capture merchant ships as prizes of war?

The correct answer is privateers. During the early 19th century, privateers were privately owned vessels that had been authorized by a government to engage in warfare and capture enemy merchant ships. This practice was particularly common during times of war, where governments would issue letters of marque to private ship owners, allowing them to act on behalf of the state to seize ships and cargo belonging to enemy nations.

Privateering was an important aspect of naval warfare at the time, as it expanded the naval capabilities of nations without the need for direct investment in a larger navy. Privateers operated similarly to pirates but were distinguished by their legal authorization to engage in such activities against designated enemy nations. Hence, they played a crucial role in commerce raiding and disrupting enemy trade routes.

Frigates, although used during this time period, were military vessels operated by the state and were not classified as privateers. Submarines did not come into use until later in naval history, so they would not have been involved in capturing merchant ships at that time. Corvettes, while also naval vessels, were typically smaller and served different roles, primarily in escorting and patrol duties rather than focusing on capturing merchant vessels. Thus, privateers stand out as the correct answer for this