Which country borders the United States to the south?

Mexico is the country that borders the United States to the south. The United States shares a long boundary with Mexico, which runs approximately 1,954 miles. This border is significant not only geographically but also culturally and economically, influencing trade, immigration, and relations between the two nations. The U.S.-Mexico border is well-known for various landmark crossings and is a focal point of discussions on immigration and security policies.

The other options provided do not share a direct land border with the United States. Canada lies to the north, making it the largest neighboring country by land borders. Colombia is located further south in South America and does not border the U.S. The Bahamas, being an island nation, is situated to the southeast of Florida and is separated by water, thus not sharing a land boundary with the United States. Understanding this geographic relationship is essential for context around U.S. foreign policy and regional issues.