USS Roanoke was a wooden-hulled Merrimack-class screw frigate built for the United States Navy in the mid-1850s. She served as flagship of the Home Squadron in the late 1850s and captured several Confederate ships after the start of the American Civil War in 1861. The ship was converted into an ironclad monitor during 1862–63; the first ship with more than two gun turrets in history. Her conversion was not very successful as she rolled excessively and the weight of her armor and turrets strained her hull. Her deep draft meant that she could not operate off shallow Confederate ports and she was relegated to harbor defense at Hampton Roads, Virginia for the duration of the war. Roanoke was placed reserve after the war and sold for scrap in 1883.