The difference in seaworthiness is abundantly clear. These American ironclads were more akin to gunboats, and mostly used on rivers (fighting for control of the Mississippi was a huge deal in the war). They were built comparatively cheaply, for a specific, immediate conflict. They often only had steam engines and lacked the endurance for transoceanic travel.
The British ironclads were built to project imperial power across the globe. The continued use of sail was important to extend endurance to reach far away places.
This was a British oceangoing ironclad, launched in 1860: https://en.wikipedia.org/wiki/File:HMSWarrior.JPG
The difference in seaworthiness is abundantly clear. These American ironclads were more akin to gunboats, and mostly used on rivers (fighting for control of the Mississippi was a huge deal in the war). They were built comparatively cheaply, for a specific, immediate conflict. They often only had steam engines and lacked the endurance for transoceanic travel.
The British ironclads were built to project imperial power across the globe. The continued use of sail was important to extend endurance to reach far away places.