General Daniel Sickles
Secretary of State William Seward
Fanny White - although she died in 1860 - her affiliation with Daniel Sickles was legendary and her earnings in antebellum New York made her a wealthy woman. She married in 1859 and changed her name to Jane Augusta Blankman. When she died at 37, her fortune was valued (in today’s dollars) between 1-2 million.
Edit - Several players guessed P. T. Barnum as the answer to the third part of the question, but Barnum came from Connecticut.
The fame of Sickles' sometime companion Fanny White has escaped me during my thus far sheltered life. The only Fanny White I ever heard of was my great aunt, who was born in 1888.