nothing
Yes; Mexican and American laws allow for a person to hold dual citizenship.
Yes, but not until later in his life.
No, he is full citizen of the U.S. because he was born in the U.S.
No, but he had plans of becoming one but was killed before he could apply. He loved this country and used to say he should have been born in New York.
Both. In Mexico (as in the United States) everyone born in its land has rights to its citizenship. So in your case, since you gave birth in Mexico, your baby has the right to be a Mexican citizen....
The Citizens United Ruling
Is Your Dog a Canine Good Citizen
Assimilation of Japanese Americans Post World War II
Old Media vs. New Media in American Story Narration