Reply: It is found in the Constitution of the United States, Article II, Section 1, Clause 5:
No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty five Years, and been fourteen Years a Resident within the United States.
2. What does it mean in the Constitution when it says "natural born Citizen?"
From Black's Law Dictionary, Sixth Edition: "Natural born citizen. Persons who are born within the jurisdiction of a national government, i.e. in its territorial limits, or those born of citizens temporarily residing abroad."
3. I am in the U.S. Army, a natural born citizen, and my wife is a U.S. Citizen, natural born. If my son is born in Germany (Military hospital or not), and has a U.S. Consular Report of Birth Abroad, and a German birth certificate can he become President of the United States?
Yes, since your son was born of citizens temporarily residing abroad, as in the military service, then he may become eligible to be president. Of course he must still "have attained to the Age of thirty five Years, and been fourteen Years a Resident within the United States."
Two cases in point: (1) George Romney of Michigan who ran for president in 1968. Mr. Romney was born in a Mormon community in Chihuahua, Mexico. His parents were U.S. citizens so he was a natural born citizen. (2) John McCain of Arizona was a candidate in 2000. McCain was born in Panama where his father was stationed in the service, so he would also be "natural born."