The San Ysidro International Checkpoint is a border port between the United States and Mexico, located between the cities of San Ysidro "San Ysidro (San Diego County, California)"), California and Tijuana, Baja California. It is the largest international crossing in the world due to more than 25 million crossings by car per year and more than 7 million people on foot.[2] The international crossing marks the beginning of Interstate 5 in California and Federal Highway No. 1 in Mexico.

After the American Invasion of Mexico in 1846-1847, the Treaty of Guadalupe-Hidalgo was signed a year later, drawing the border line between both countries, causing the Tía Juana Ranch, property of Santiago Argüello, to be divided. On August 6, 1874, the first border customs office was established. Later it would be called "Garita Porfirio Díaz".[3]​.

In 1887, the real estate firm Hart and Stern developed Tía Juana City on the site currently occupied by Las Americas Premium Outlets; It consisted of a single street with a pharmacy, a salon, a hotel and a shoe store and a few houses scattered beyond. Floods devastated buildings in 1891 and 1895. The city of Tía Juana was not rebuilt immediately and settlers moved to higher ground.[4]​ With the formation of San Ysidro, after several floods and the consolidation of the town of Tijuana, Mexico; a border inspection station was established.

In 1933, a federal building was built for border customs. The building has a Spanish Renaissance architectural influence, being designed by the office of the Supervising Architect of the Department of the Treasury; Construction was performed by Robert E. McKee of El Paso, Texas, who was paid $93,800. The inauguration was in the early summer of 1932. In May 1933 the building was completed; It was quietly put into use without a formal dedication ceremony.[5]​.

When the 60's arrived, Tijuana was full of growth and change. To accommodate the growing border crossing, the Federal Government of Mexico expanded the country's entry point to San Ysidro, opening the now demolished Mexico Gate in 1964.

It was not until the 1970s that an expansion of the international port of entry was built to meet the needs of the time and the projected growth in the coming years.[6]​.

After the events of September 11, 2001, security and surveillance at the border increased waiting times at crossings and reduced a series of social conflicts that were registered in that area, such as illegal crossings and the image of a lawless border. car, a new pedestrian crossing building (Pedwest) and the relocation of the crossing to Mexico through the El Chaparral Garita "El Chaparral (border crossing)"), inaugurated in 2012.[9]​.