Ironclads! A Program for Students and Adults



When the U.S.S. Monitor and the C.S.S. Virginia fought to a stalemate during the Battle of Hampton Roads in March of 1862, they changed the course of naval architecture, leading to the development of steel naval ships we know today.


In this set of activities, students of all ages can take a look at examples of ironclad ships from the Civil War era, study period documents about the Battle of Hampton Roads, and participate in an activity or two with simple household supplies to create an origami cannon, and test their ship design engineering skills.









View a slide show of various ironclad ships that were built by the Union and the Confederacy (this information is also available as a single sheet download).




Examine half a dozen period documents and answer questions about the ships and the battle.




STEM Activity: Foil Boat Engineering Challenge
Use heavy-duty foil to test ship hull designs.

Origami Cannon
Fold construction paper into an origami cannon.



Ironclad Compare and Contrast

View a slide show of various ironclad ships that were built by the Union and the Confederacy.
This information is also available as a single sheet download.

The Battle 
of Hampton Roads

In this image, the Union U.S.S. Monitor clashes with the Confederate C.S.S. Virginia (ex-Merrimac) in the waters of Hampton Roads on March 9, 1862.

These two famous ships were very different in their designs. However, both of them advanced the new concept of ironclad ships.

Did you know that more of these unusual vessels were built? Click through the slides to see more examples from North and South!

Examples of Confederate Ironclads:

Look for similarities and differences between these ships and the original C.S.S. Virginia.

The Virginia was the most successful Confederate ironclad and the prototype for almost all the other 50 ironclads the South attempted to build. The ship’s simple design of a sloped and iron plated casemate had proven efficient at deflecting cannon shot.

However, only a few large offensive ironclads modeled on the Virginia were constructed to challenge the Union blockade. Most Confederate ironclads had a smaller casemate, fewer cannon, and were shallow draft defensive weapons designed to protect major cities against naval attack.

Nearly all Confederate ironclads also shared the problems that had plagued the Virginia. These challenges arose from the South’s limited industrial capacity. Issues such as faulty engines, a shortage of iron, a lack of machinery, an insufficient transportation network, and an absence of skilled workers only grew worse as the war continued.


Union Ironclad Examples:

Look for similarities and differences between these later “monitors” and the original U.S.S. Monitor.

When news of the Virginia arrived in the North, the Union sought plans for an ironclad of their own advertising for:

“…the construction of one or more iron-clad steam vessels of war, either of iron or of wood and iron combined, for sea or river service, to be not less than ten nor over sixteen feet draught of water…”

Originally three different designs were selected; these became the Monitor, the Galena, and the New Ironsides. In addition to building several dozen variations of coastal Monitor class ironclads (Onondaga), the Union converted paddlewheel river boats on the Mississippi into ironclads (Essex, Choctaw, Osage, & Ozark) and experimented with ironclad designs that would be sea worthy on the open ocean (Keokuk & Roanoke).


History Detective

When the USS Merrimack was reborn as the CSS Virginia, she embodied two technologies that would come to define the future of naval warships; armor and steam. During the March 1862 Battle of Hampton Roads, the Virginia destroyed two traditional Union ships becoming the most successful Confederate ironclad of the Civil War. Yet, it was the very design of this revolutionary ship that led to the demise of the Virginia just 2 short months later at the hands of her own crew!

How did the repurposing of the USS Merrimack in construction and her famous encounter with the Union ironclad Monitor lead to the inglorious end of the CSS Virginia?

Let’s follow the evidence! Read each of the documents and think about the questions that accompany each one.

Document #1

1856 Lithograph “The US Auxiliary Screw Steam Frigate Merrimack

Designed to cruise long distances of open ocean on sail power, frigates such as the USS Merrimack were the largest warships built by the US Navy . As an ‘auxiliary screw steam’, her engines turned a screw (propeller) meant to be used only in emergency situations such as combat or unfavorable wind.

Early steam engines were unreliable. The Merrimack’s engines frequently malfunctioned and proved to be inadequate to propel the ship. It was partly these issues which brought the Merrimack to Portsmouth’s Naval Shipyard in 1860.

Question: How might the original design of the Merrimack cause issues when the ship was rebuilt as the ironclad CSS Virginia?

Document #2

“Sketch of the CSS Virginia” from Records of the Bureau of Ships (1862-1909)

The design of the CSS Virginia utilized a heavy iron plated casemate or armored bunker for cannons built atop of the remaining wooden frame (hull) of the USS Merrimack. The Virginia shocked the public when she not only floated when released from the dry docks, she floated too well! The ship’s armor only extended to her projected waterline and initially the Virginia sat too high in the water exposing about a foot of her vulnerable wooden hull. In addition to tons of coal and ammunition, scrap metal was placed in the bottom of the ship to lower the Virginia in the water from 19 feet to 22 feet (called a ship’s draft). Still needing some finishing details completed and without even having a real trial run, the Virginia steamed into Hampton Roads to do battle with the Union in early March 1862.

If the protective armor of the Virginia barely came below the waterline when fully loaded with ammunition and coal, how might fighting extended battles endanger the ship?

Document #3

1862 Union “Map of Hampton Roads depicting the March 9, 1862 battle between the USS Monitor and the CSS Virginia (formerly the Merrimack)”

Two additional issues plaguing USS Merrimack arose from her hull. Designed as a sailing ship, the Merrimack was never efficient under steam power and her deep draft meant she sat too low in the water to enter most American ports. These issues also cursed her during the two day Battle of Hampton Roads when reborn as the ironclad CSS Virginia. The successful first day’s action destroying the USS Congress and Cumberland while running the USS Minnesota aground ended with the lowering tide forcing the Virginia back to Portsmouth. Returning to finish the Minnesota on the second day, the Virginia clashed with the newly arrived USS Monitor.

“(we) hovered about each other in spirals… for two hours the cannonade continued without perceptible damage to either combatant-Then an accident occurred-“

– Captain Henry Ashton Ramsey, CSS Virginia

Question: Using the 1862 “Map of Hampton Roads” and knowledge of the CSS Virginia, what might be the accident reported in Captain Ramsey’s account?

Document #4

The Merrimac was aground! The propeller churned the mud and water furiously, but the ship did not stir…”

Captain Henry Ashton Ramsey, CSS Virginia

886 Lithograph “The Monitor and Merrimac: The First Fight Between Ironclads”

Hampton Roads is blessed with a deep water channel, but this flanked by dangerous sandbars that require local knowledge to negotiate safely, especially as the tide lowers. The deep draft of the CSS Virginia and her poor engines resulted in her running aground for over 15 minutes during the battle. Once free, the Virginia reengaged with the Monitor for another hour before the much shallower draft Union ironclad retreated to water where the Virginia could not follow. With the tide dropping, the Confederates feared they would be stranded in the river for another 24 hours if they did not return the Virginia to Portsmouth immediately.

Shallow water was not the only concern. Two days of burning coal and firing cannons had made the Virginia much lighter. She now sat higher in the water revealing several inches of the unarmored wooden hull bellow the casemate.

Question: Knowing the issues afflicting the Virginia, what improvements could the Confederates attempt to allow the ironclad to better engage the Union fleet?

Document #5

“The ship was docked….and a course of two-inch iron [was added] on the hull. The ship was brought a foot deeper in the water, making her draft 23 feet.

-Captain Catesby Ap. R. Jones, CSS Virginia

Now better amored, heavier, and sitting even lower in the water; the CSS Virginia attempted twice more to engage the Union fleet in battle during the spring of 1862. However, the Confederate ironclad was no longer effective. Union vessels simply refused to fight by waiting in shallow water out of range of the Virginia and protected by powerful cannon on shore. When the Union landed over 100,000 soldiers in May to capture Hampton Roads, the Confederates faced a dilemma. 

1862 Union “Military Reconnaissance of Hampton Roads”

A fathom is a unit of measure for water depth equal to 6 feet.

The water depth of the channel is measured in fathoms and highlighted on the map. If the Virginia needed nearly 4 fathoms to safely maneuver, what course would she take starting from Craney Island at the bottom right and moving to the upper left of the map towards Richmond?

Document #6

Now, the enormous weight of her shield and battery, kept the Virginia, all the time, just hovering between floating and sinking. She was sluggish, sodden and entirely irresponsive …”

-Col. William Norris, Confederate Secret Service Bureau

As Norfolk fell to Union forces, the Confederates briefly considered fleeing toward the open ocean before settling on moving the CSS Virginia further up the James River. However, this would only work if the ship could be lightened to 18 feet of draft to safely pass over sand bars while staying away from the large Union cannon lining the shore. The ship’s crew spent the evening of May 10, 1862 throwing everything possible overboard, lightening the Virginia by several tons. Unfortunately, a hard west wind blew all night making the river even more shallow than normal. With 2 feet of her unarmored hull now exposed and in no shape to fight her way out of Hampton Roads, the Virginia was set afire at dawn to keep her from falling into enemy hands.

1862 Lithograph “Destruction of the Rebel Monster ‘Merrimack’ off Craney Island May 11th 1862”

The CSS Virginia ended the age of wooden sail powered warships with a revolutionary combination armor and steam. Yet, it was also this design which caused her demise. The use of the deeply flawed USS Merrimack in the ship’s construction and her battle with the Monitor left the Virginia a ship that could either be a heavily armored threat or a vessel that was maneuverable in coastal waters; but not both.


STEM Activity: Foil Boat Engineering Challenge

“Hundreds – I may say thousands – asserted she would never float. Some say she would turn bottom side up….public opinion generally around here said she would never come out of the dock.”

-John L. Porter, designer of the CSS Virginia

As the Union Navy hastily evacuated Portsmouth’s Navy Yard in April 1861, they set afire and sank the sail powered wooden cruiser USS Merrimack. However, burned only to the water line, the ship would be salvaged by the Confederacy and modified into a completely different design; the steam powered and iron plated CSS Virginia.

This new design required 800 tons of iron, more iron than the Confederacy even had available at the time, to cover the ship in 4 inch armor plates. Delays in acquiring and shaping the needed iron meant the construction of the Virginia took almost an entire year.

When the Virginia released from the dry dock in February of 1862, many believed she would end up at the bottom of the river!


You will need: Heavy-duty aluminum foil, cut into four inch squares; some pennies; a sink or dishpan with an inch or two of water in it.

1. Using just your hands, shape the aluminum foil square into a boat shape of your own design with the goal of holding as much weight as possible without sinking.

2. Before adding any weight, try to predict how many pennies your boat can hold before it sinks!

3. Test your design and hypothesis by placing your boat into the water. Start putting the pennies, one at a time, in the middle of the boat first, then work your way towards the outsides.

How well did your design work? How close was your prediction to the outcome? What could you have done differently in design that may work better?

Origami Cannon

During the Battle of Hampton Roads, the CSS Virginia mounted 10 cannon which weighed a combined 51 tons! That’s equivalent to the weight of more than 17 modern-day cars! Let’s create our own origami cannon we can take home from the museum by folding paper.


1. Fold your paper in half long ways so that the corners meet and create a crease. Then open the paper up.

2. Fold the top two corners down to the center crease, similar to when you are making a paper airplane.

3. Fold the newly created triangle at the top of your sheet down along its bottom edge, lining the top of the triangle with the center crease. Your paper should now have an envelope shape.

4. Flip your paper over. Fold the triangle at the top over, reversing the crease along its bottom edge and bringing the point of the triangle to the center crease of your paper.

5. Flip your paper over. With the triangle side down, fold bringing the edges of the paper together along the center crease.

6. Hold the paper with the center crease down, left hand at the bottom corner and with your right hand pinch the bottom left corner of the triangle, pulling it to about a 45 degree angle and fold. This will be your cannons base.

7. Holding your paper with two hands, open the top of the paper up slightly. Curl one side inward towards the center crease. This will begin to create the barrel of your cannon.

8. Still holding the paper with two hands, curl the other side of the paper over your cannon barrel, tucking the paper as you curl into the pocket created by folds at the rear of the cannon. Tuck the whole way around.

You may need to adjust your cannon base to allow it to stand once you are done.