What does the term "south of the U.S." typically refer to?

The term "south of the U.S." typically refers to Mexico, which is the country that shares the southern border with the United States. This geographical description highlights the direct relationship between the U.S. and Mexico, with the U.S.-Mexico border being one of the most significant international boundaries in North America.

In the context of North American geography, Canada lies to the north of the U.S., which makes it an incorrect choice for a term that indicates "south." The Gulf of Mexico is a body of water located southeast of the U.S. but does not refer to a landmass or country, making it less relevant in this context. Central America, while geographically south of Mexico, is not typically referenced in a general statement about what lies directly south of the U.S. Moreover, when people refer to "south of the U.S.," they usually mean Mexico specifically rather than the broader region of Central America.