How many Hamilton Fishes have there been?

Five, dating back to 1808, when the first Hamilton Fish was born to Nicholas Fish (1758-1833), Revolutionary War patriot and friend of Alexander Hamilton, for whom Nicholas named his son.

Each Hamilton Fish was father to another one, in this order:

Hamilton Fish (1808-93)
Hamilton Fish (1849-1936)
Hamilton Fish, Jr. (1888-1991)
Hamilton Fish, Jr. (1926)
Hamilton Fish III (1951)

The three middle individuals have all served as Republican congressmen from New York.

In a break with tradition, Hamilton III is a Democrat who published the left-wing magazine The Nation from 1977 to 1987.