Answer:
Andrew Carnegie worked with steel and used the business method of "vertical integration" (in which he took all parts of the steel making process into his own hands to decrease his spending, improve quality of the steel, and monitor work during each step). This isn't really relevant to the question, but if you want to more more enlightened, the method of "horizontal integration" was a creation of John Rockefeller, in which he allied with other companies to eliminate competition. Eventually, J.P. Morgan took over Carnegie's business and founded the United States Steel Corporation.
Now, Cornelius Vanderbilt worked with steamboats and railroads, eventually dominating the railroad business. His money went into the founding of Vanderbilt University, in which his name is most remembered. He did, however, replace the iron rail with a much more efficient steel rail.
I hope this helped,
Megan