Everyone in the colonies was a British citizen until July 4, 1776.
Since Hamilton emigrated to the United States in 1772, he would have become a citizen via the Declaration of Independence. He was clearly a citizen after ratification of the Constitution in 1789, because he was confirmed as the first Secretary of the Treasury under President Washington.
-PJ
You don't say. ;-)
"Subject." Not "citizen."
That is the entire distinction between the two. No, they are not at all the same.
"Subject" links to British common law. "Citizen" links to Vattel and Switzerland.
We chose the Vattel meaning by choosing the word "citizen".