Okay, wiseguys: if I asked you who was the richest man in the United States in 1970* 1870, you might well say "Cornelius Vanderbilt"--and by all that I know, that would be correct. But after Vanderbilt, who was the second richest? No Googling, now--but I've got you there, haven't I?
I just picked up a plausible answer, reading TJ Stiles' First Tycoon. I admit I had never heard of the guy. For a quick summary, go here.