Primarily remembered for designing the first iron-clad warship, Ericsson was born in the Värmland region of Sweden and displayed an early talent for science and mathematics. As an adolescent he worked as a draftsman on the Swedish Göta Canal project and later served as a land surveyor in the Swedish Army.

Ericsson went to London, England, in 1826 to pursue a career in engineering. During the next thirteen years, he developed an interest in propulsion systems, making several improvements to steam engine design, experimenting with the use of compressed air for power, and working on a device he termed the caloric engine. In 1829, Ericsson and John Braithwaite designed and built a locomotive which they entered in the Rainhill Trials, a competition to find the best new locomotive design. The competition was won George Stephenson's famous locomotive, the Rocket. Ericsson later turned his attentions to naval...