Where in the constitution does it say to be president one must be us-born?

Article Two Section One of the U.S. Constitution states a candidate for President must be a natural born citizen. This means that a person can be born on any land that is considered U.S. property, such as an embassy or a military base. Article Two also states the President must be at least 35 years old and have been a resident within the U.S. for fourteen years.