Kansas City Southern (KCS) was a transportation holding company with railroad investments in the United States, Mexico, and Panama that existed from 1887 to 2023. The KCS rail network included about 7,299 miles (11,747 km) of track in the U.S. and Mexico.

The Texas Mexican Railway International Bridge is an international railway bridge across the Rio Grande and U.S.-Mexico border between Laredo, Texas, and Nuevo Laredo, Tamaulipas, the only rail link between these cities. Owned and operated by CPKC, the single-track bridge is the busiest rail border crossing in North America. It is also known as the Laredo International Railway Bridge and Puente Negro.