Edward Fry was impresario for the Astor Place Opera in 1849 at the time of the famed Shakespeare riots, when dozens of New Yorkers were killed.
Adam Forepaugh was a wealthy horse trader who more-or-less accidentally took over a circus, but gave P.T. Barnum a run for his money in post-Civil War America.
J. Fred Zimmerman was one of a small group of men, fittingly called the Theatre Syndicate, who controlled a majority of theatres on the east coast, essentially determining what plays would be staged and what actors would work.