Which industry expanded as a result of the invention of the Bessemer process?

I don't know for sure if this is it, but I'd say the railroad industry.

This process was a method of producing very high-quality steel. It was done by shooting the air onto the molten steel, to burn the carbon and impurities. The process is named after Sir Henry Bessemer, who developed the process in the 1850 s. In America, steel production was in huge quantities but the quality was not up to the mark. In the production of suspension bridges and other large structures, it was necessary to have high-quality steel. The Bessemer method revolutionized the steel industry and led to the advancement of construction and shipbuilding. A similar method was patented by William Kelly which he got patented in 1857.