I am aware of that. Plenty of time to have made known their intentions of becoming citizens if they were going to. That it took so long argues against their intent to be citizens, which argues against Rubio's "natural born status" even under the theory that the founders were indulgent to the idea of children born of foreigners being "natural born citizen"(s).
His mother had already become a citizen and his father was in the process, delayed only by the need to travel to support the family. In any case, he had appeared before the system (magistrate) to declare his intent.
That was all that was required by the 1790 citizenship law, iirc, 3 years resident and appearance before a magistrate to declare intentions.
If the original language is seen in the constitution, then the original process is seen in the first law passed by congress to codify that intent.
Act of March 26, 1790 (1 Stat 103-104) (Excerpts) That any alien, being a free white person, who shall have resided within the limits and under the jurisdiction of the United States for the term of two years, may be admitted to become a citizen thereof, on application to any common law court of record, in any one of the States wherein he shall have resided for the term of one year at least, and making proof to the satisfaction of such court, that he is a person of good character, and taking the oath or affirmation prescribed by law, to support the Constitution of the United States, which oath or affirmation such court shall administer; and the clerk of such court shall record such application, and the proceedings thereon; and thereupon such person shall be considered as a citizen of the United States. And the children of such persons so naturalized, dwelling within the United States, being under the age of twenty-one years at the time of such naturalization, shall also be considered as citizens of the United States. And the children of citizens of the United States, that may be born beyond sea, or out of the limits of the United States, shall be considered as natural born citizens: Provided, that the right of citizenship shall not descend to persons whose fathers have never been resident in the United States:
Significant because it is the first to define a process resulting in citizenship.
1. 2 years resident in the US
2. At least one year resident in the state applying from
3. Applying to any common law court of record
4. Prove good character
5. Take oath to support Constitution
This must be taken in light of Kentucky County, Virginia (indeed, of all of the frontier) which in 1780 was divided into Fayette, Lincoln, and Jefferson Counties, all of which became the state of Kentucky in 1792, but PRIOR to that was a part of the state of Virginia.
One of my books on methodist history includes this piece about a minister named David Haggard at about 1787. "He seems to have lived in or near burkesville, Ky., as we have in our possession a copy of the action of the County court of cumberland County, granting him license to solemnize the rites of matrimony, as a minister.." (Methodism in Kentucky, W.E. Arnold, Herald Press (1935), p 81.)
What really are the requirements of this law? Residency, acceptable reputation, and oath of allegiance.
But, as you read of this territory of the country during this time you discover how wild it was, how flooded with immigrants it was, and how the intent of the settlers really was the driving factor.
My point is simply the comparing of that time with the life and actions of Marco Rubio's father.