#james yard

I hadn't meant by records, seeing as how we struggle to this day to find any concrete records of Hamilton's true birthyear. But yeah, his contacts. A good, but small, handful of Hamilton's associates from the West Indies were also located at New York, or the Colonies in general—And others at least remained in contact with him or his family. To name a few, Hamilton's father and cousin, Anne Mitchell, remained in contact with him, and Anne even visited and wrote to Eliza after his death. We have scarce surviving correspondence between Hamilton and his father, but if he was planning to let him move to NYC to live with them; it can be speculated that Eliza may have written a few letters to him, or he sent his own to others in New York.

Or the can of worms Edward Stevens' offers, he was Hamilton's boyhood best friend from St. Croix, and attended King's College where they attended the same class club and had shared some of the same friends, Nichoals Fish, Robert Troup, etc. If there was one person who we had to trust to know Hamilton's birthyear out of the surviving relatives or friends he had at the time, it would have likely been Stevens. Stevens's brother-in-law, James Yard, knew a good amount about Hamilton and his childhood considering later he was able to provide information for Timothy Pickering, who was planning to write a biography about Hamilton. The same one that mentions the possibility of Thomas Stevens being Hamilton's real father. Additionally, there is the Kortright family; Monroe's wife, Elizabeth Kortright Monroe, was a cousin of Hester Kortright Amory, Stevens's wife. And Elizabeth K. Monroe's uncle was one of Hamilton's employers from the Island, Cornelius Kortright, who worked with Nicholas Cruger. He helped handle Hamilton's financial dealings when he first made it to the Colonies. With all this being said, I highly doubt everyone was just keeping this a secret. Especially with their close relations to James Monroe, one of Hamilton's rivals, who could have easily used it against him.

And going back to Cruger, he would have definitely known Hamilton's contrasting age considering he was his employer at the Cruger Counting house. He also moved back to New York and saw Hamilton again, even once there were rumors spreading by the press that Hamilton could become governor with him as lieutenant governor in 1795. Catharine Church, the eldest Church daughter, married Bertram Peter Cruger, Cruger's son.

And all of Hamilton's associates from the Colonies roughly followed the 1757 belief. But you are right saying; “and frankly, I wouldn't know off hand when many of my close friends were born either.” Because as @46ten as recently added on, we are putting way too much emphasis on a birth year than what those of that day would. We value birth dates more strongly than when even as recently as a century ago, we did not. Today birth dates are now widely used for identification, but back when containing written documents was more of a hassle (As finding documents from Nevis has proven), not many were inclined to do such. In a day in age, where many families didn't even celebrate birthdays often, it wasn't much more than a passing thought for most. There is even a humorous story of Eliza forgetting JCH's birthday when he was young;

John is as industrious as usual and this Evening has ascertained that he is not more than twelve last August. I had thought him to have been thirteen but he is not more than twelve.

Elizabeth Hamilton to Philip Schuyler, [1804]