The United States and Mexico share a long border that stretches approximately 1,954 miles. This border is the most frequently crossed international boundary in the world, facilitating significant trade and cultural exchange between the two nations. The Rio Grande river serves as a natural boundary for part of this border. Both countries have strong economic ties, with NAFTA (now replaced by USMCA) promoting trade and investment. The United States is one of Mexico's largest trading partners, and many Mexican citizens live and work in the U.S., contributing to the diverse cultural landscape of the region.