The first battle between Ironclad warships was between the CSS Virginia and the USS Monitor. While the USS Monitor was ill-suited for open ocean (as it turns out), the CSS Virginia would have been capable of moderate seas.
That is true, however the first use of Ironclads was in the Crimean war, only the French had them so there were no ship to ship battles
They were only good for about 4 kts under their own power and had to be towed over long distances. British had two but didn't get them to the Crimea in time for combat.
Once you have several nations building Ironclads a battle between them becomes almost inevitable.
Another innovation of modern warfare, was the naval mine, developed by the Confederates to try and prevent Union warships from entering bays or rivers. As it turns out, land mines were later developed from this.
Naval mines had been used (or at least known of) for several centuries in the west. Chinese use may go back several centuries before that. Problems were sealing the mine (black powder being notoriously subject to failing when wet/damp) fusing (getting the thing to go off when you want it to).
From wiki for the 18th Century:
"
In 1812 Russian engineer
Pavel Shilling exploded an underwater mine using an
electrical circuit. In 1842
Samuel Colt used an electric detonator to destroy a moving vessel to demonstrate an underwater mine of his own design to the
United States Navy and President
John Tyler. However, opposition from former President
John Quincy Adams scuttled the project as "not fair and honest warfare."
[10] In 1854, during the unsuccessful attempt of the Anglo-French fleet to seize the
Kronstadtfortress, British steamships HMS
Merlin (9 June 1855, the first successful mining in history),
HMS Vulture and HMS
Firefly suffered damage due to the underwater explosions of Russian naval mines. Russian naval specialists set more than 1500 naval mines, or
infernal machines, designed by
Moritz von Jacobi and by
Immanuel Nobel,
[11] in the
Gulf of Finland during the
Crimean War of 1853-1856. The mining of
Vulcan led to the world's first
minesweeping operation.
[12][13] During the next 72 hours, 33 mines were swept.
[14]
The
Jacobi mine was designed by German-born, Russian engineer Jacobi, in 1853. The mine was tied to the sea bottom by an anchor. A cable connected it to a
galvanic cell which powered it from the shore, the power of its explosive charge was equal to 14 kilograms (31 lb) of
black powder. In the summer of 1853, the production of the mine was approved by the Committee for Mines of the
Ministry of War of the Russian Empire. In 1854, 60 Jacobi mines were laid in the vicinity of the Forts Pavel and
Alexander (
Kronstadt), to deter the
British Baltic Fleet from attacking them. It gradually phased out its direct competitor the
Nobel mine on the insistence of Admiral
Fyodor Litke. The Nobel mines were bought from Swedish industrialist
Immanuel Nobel who had entered into
collusion with Russian head of navy
Alexander Sergeyevich Menshikov. Despite their high cost (100
Russian rubles) the Nobel mines proved to be faulty, exploding while being laid, failing to explode or detaching from their wires and drifting uncontrollably, at least 70 of them were subsequently disarmed by the British. In 1855, 301 more Jacobi mines were laid around Krostadt and
Lisy Nos. British ships did not dare to approach them"
Yes the American Civil war saw the much larger use of mines than any war before it.
And it was my understanding that the Civil War was the first to use railroads as a strategic military tool, moving not only troops and supplies, but weapons, like railway artillery - particularly mortars.
See:
Grand Crimean Central Railway - Wikipedia
It was more tactical supply than strategic, I don't know how much use of railways was done in England and France to bring supplies/men to the docks to load on ships.
Railways were a booming industry in the mid 1800s, England may have gone from 90km of track in 1829 (mainly horse drawn) to 1500km of track in 1839 to 8000km of track in 1850.
The US was bit behind in getting started but considering the distances involved in the US, caught up pretty well if not surpassing Britain in the 1850s.