Mexico City was the capital of Mexico, a country neighboring the United States of America to the south. In 2042, a major earthquake hit the city, destroying large amounts of it. Use of Mister Handy robots in the reconstruction made them one of the most popular robots of the 21st century.
In the year 2051, seeking to protect business interests and their oil supply, the United States began to exert increasing pressure on their neighbor, citing the political instability and pollution stemming from Mexico as a threat to the United States. Various economic sanctions served to destabilize Mexico, and the United States military entered Mexico to keep the oil refineries running and making sure oil and fuel continue to make their way north across the border, at Mexico's expense.
On October 23, 2077, the Great War occurred, and the city was hit with large amounts of nuclear weapons, turning it into a radioactive ruin. Many citizens were forced to flee to surrounding settlements and farmlands. Not long after the war, scavengers and raiders started to infest the city and criminal activities became bigger than what they were before the war. According to Raul Tejada, a ghoul who lived before the Great War, the city had a high crime rate.