Conversation so far:
What was the steel empire that Andrew Carnegie was a part of?
By 1889, the U.S. output of steel exceeded that of the UK, and Andrew Carnegie owned a large part of it.
What was done with the steel once Andrew Carnegie's Keystone Bridge Company acquired it?
The steel that Andrew Carnegie's company owned was made into iron products, such as armor for gunboats, cannons, and shells, as well as a hundred other industrial products

Question: What was the Bessemer process?
Self-contained rewrite: What was the Bessemer process?