Point of Order:
First, to be a citizen of a country, that country has to exist. On July 4, 1776, thirteen British colonies declared their independence from the British Empire. Although they did this as a single act among them, such action only severed ties. The action did not create a unified country but thirteen independent states. subsequent agreements provided for a unified army, but did not create a country.
The United States, in its current form, did not come into existence until its constitution was ratified (June 21, 1788). However, it could be argued that the U.S. was created by the earlier Articles of Confederation (March 1, 1781). The Constitution has no retroactive definition of citizenship - merely recognizing the citizens of the member states (the former colonies) as its citizens. The Articles more closely represent a treaty between states than a unified governing state.
Therefore, I question the claim of the date of July 4, 1776 as being a birthday for a person being BORN a U.S. citizen (as opposed to becoming a citizen later in life when a document forming government was ratified). Perhaps June 21, 1788 is the proper LEGAL date?
I shall agree that July 4, 1776 is the first date where a person born in the colonies may not be born a British subject. Persons born between 1776 and 1788 are more likely citizens of their respective colony-states than that of a unified government.
The OP suggested that citizenship of the independent colonies may have started with the treaty which ended the conflict and led to recognition of the colonies of independent states (the Treaty of Paris). Again, that's not an event that creates a unified government out of the colony-states.
My take on this is that persons born prior to July 4, 1776 were born British. Persons born between 1776 and 1788 are citizens of their respective colonies. Only persons born [on or] after June 21, 1788 were born U.S. citizens (and also citizens of their respective states).
NB: Having two levels of citizenship (member state and national) is not unheard of. Switzerland has a three level system (federal, cantonal, and village).
Jan 14 2017, 4:18 PM