While looking at YouTube for ACW naval documentaries I discovered this early drama. It's called Hearts in Bondage (1936), and it stars James Dunn, Mae Clarke, and David Manners. It covers the creations of USS Monitor and CSS Virginia and the battle between both.
I love how the Southerners all seem to speak with a Yankee accent...must be a bad casting director!
Interesting - James "Jimmie" Dunn is possibly best known today as the first of many of Shirley Temple's "leading men" when she got to the "big time"; here's a still of them together with Claire Trevor from Baby Take a Bow: