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
What was the Bessemer process?
The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace.
What was done with the steel that Andrew Carnegie's Keystone Bridge Company produced?
Andrew Carnegie's company was the largest manufacturer of pig iron, steel rails, and coke in the world, with a capacity to produce approximately 2,000 tons of pig metal per day.
How profitable was Andrew Carnegie's steel industry?
Andrew Carnegie's company was the first corporation in the world with a market capitalization over $1 billion.
Did Andrew Carnegie's empire include any other business?
In 1883, Andrew Carnegie bought the rival Homestead Steel Works, which included an extensive plant served by tributary coal and iron fields.
Are there any other interesting aspects about this article, besides what the Bessemer process is, what other products Andrew Carnegie's company made, how profitable they were, and other businesses that he owned?
A special vault was built to house the physical bulk of Andrw Carnegie's steel buyout, which was nearly $230 million worth of bonds.

Question: Did he finally marry?
Self-contained rewrite: Did Andrew Carnegie finally marry?