Conrad Black is the author of Franklin Delano Roosevelt: Champion of Freedom and Richard M. Nixon: A Life in Full.

Having just spent four pleasant months in New York City, it was my misfortune to have to leave just before the opening of two historic sites that demonstrate the longstanding, dramatic importance of that city.

The relocation and renovation of Alexander Hamilton’s house, the Grange, reminds us that New York has been an influential city in the world since before Napoleon was emperor of the French. The house was built in 1802, two years before Hamilton died in the still hotly debated duel with Vice President Aaron Burr. It is, as one reviewer said, not Mount Vernon or Monticello — but then, Hamilton was the illegitimate son of a wandering Scot from the Caribbean island of Nevis, not a member of one of the First Families of Virginia, rich in land, slaves, and connections. But, from pictures, one can tell that it is a somehow surprisingly well-proportioned, airy, cheerfully colored and situated, and gracious home, now very close to its original location on Hamilton Heights in northern Manhattan, on the greensward that is left of its original 32 acres overlooking the Hudson and Harlem Rivers.

Hamilton was rivaled in his time as the most important New York political figure by Burr and nine-term governor George Clinton. Burr tried to pretend that the electoral votes cast for him in the 1800 election were for president and not vice president, as they were not differentiated at that time, and he drew with the real presidential candidate, Thomas Jefferson, and both came ahead of the incumbent president, John Adams. Hamilton and Adams, despite their dislike of Jefferson, judged him morally more suited to the office, and eventually put him across in the House of Representatives. Jefferson ditched Burr and amended the Constitution to avoid this anomaly, and selected Clinton for vice president. In 1808, Clinton had the distinction of running simultaneously for president and vice president, and therefore against himself (as the same person cannot hold both offices), and was defeated by Madison, whom he then served as vice president. The other great New York public figure of the time was John Jay, a prominent federalist in constitutional discussions, the first chief justice, Washington’s emissary to complete peace terms with Britain, and governor of New York, but never a man with a great deal of political traction...