What is the largest isthmus in the Western Hemisphere?

The largest isthmus in the Western Hemisphere is the Isthmus of Panama. Stretching approximately 50 miles (80 kilometers) at its narrowest point, it connects North America and South America and separates the Pacific Ocean from the Caribbean Sea. The isthmus is also home to the Panama Canal, a vital waterway for international maritime trade. Its geographical significance has made it a crucial area for transportation and commerce.