In 1862, the Union forces developed river gunboats which were the first ironclad vessels in the United States. In what river valley did these vessels see their first action?

The first ironclad vessels in the United States, specifically the Union's Monitor and Merrimack, saw their initial action in the Hampton Roads area, which is located near the mouth of the Chesapeake Bay where the James and Elizabeth Rivers converge. This pivotal encounter occurred in March 1862 during the Civil War. While the Hudson River is historically significant, particularly in the context of early American history and transportation, it was not the site of these specific naval engagements involving ironclad vessels. The correct context for the actions of these early ironclad ships is indeed in the Tennessee and Mississippi River Valleys, where they played crucial roles in the Union's riverine campaigns.