The Merrimac(the south's ship) and the Monitor(the North's ship)
The South's first ironclad warship was the CSS Virginia. This vessel was constructed from a sunken Union ship the USS Merrimack. The Confederates retooled the ship, added much armor and became the first ironclad warship of the US Civil War.
The Union Ironclad ship was the Monitor. The Confederate ship was the Virginia.
The Union ship called the USS Merrimack was captured by the South. The ship had been burned by the Union forces, but the Confederate forces took it and rebuilt it into an ironclad ship. It was renamed as the CSS Virginia.
A ship is by itself never a weapon, and that also goes for an ironclad ship. The ironclad could only be called a weapon carrier.
Ironclad ship is not required to be capitalized unless it is at the beginning of a sentence or part of a title.
Monitor
The first Ironclad ship ever made was by the northern states during the civil war was named the Monitor.
Ironclad
a ship heavily armored in iron
it was a ship made of metal
Merrimack