Under which department does the United States Merchant Marine serve?

The United States Merchant Marine operates under the Department of Transportation. This department oversees the nation's transportation systems, including the maritime industry. The Merchant Marine plays a crucial role in both commerce and national defense, ensuring the transportation of goods and personnel during peacetime and securing logistic support in times of conflict.

While the Department of Commerce is involved in various economic functions including trade and development, it does not directly manage the Merchant Marine. The Department of Agriculture and the Department of the Navy focus on different sectors; the former is primarily concerned with farming and food resources, while the latter is specifically for military naval operations. Therefore, the accurate affiliation for the U.S. Merchant Marine is with the Department of Transportation.