Abraham Lincoln called the Mississippi River “the backbone of the rebellion,” and “the key to the whole situation.” He knew it was important for the Union to control it. The South had sizeable numbers of men and supplies in Texas and Arkansas, west of the river. If the Union could control the Mississippi, the confederacy’s capability to wage war would be hurt. So Missouri, a state in the middle of the continent, became the place where the first American ironclad ships of war were built.
