The Gulf of Mexico (Spanish: Golfo de México) is an ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In Texas and Louisiana it is often called the "Third Coast," in comparison with the U.S. Atlantic and Pacific coasts. The shape of its basin is roughly oval and is approximately 810 nautical miles (1,500 km) wide and filled with sedimentary rocks and debris. It is connected to the Atlantic Ocean through the Florida Straits between the U.S. and Cuba, and with the Caribbean Sea (with which it forms the American Mediterranean Sea) via the Yucatan Channel between Mexico and Cuba. With this narrow connection to the Atlantic, the Gulf experiences very small tidal ranges. The size of the Gulf basin is approximately 615,000 mi² (1.6 million km²). Almost half of the basin is shallow continental shelf waters. At its deepest it is 14,383 ft (4,384 m) at the Sigsbee Deep, an irregular trough more than 300 nautical miles (560 km) (550 km) long. The basin contains a volume of roughly 660 quadrillion gallons (2.5 × 10⁶ km³). It was formed approximately 300 million years ago as a result of plate tectonics.

Mexico (ⁱ/ˈmɛksɨkoʊ/; Spanish: México, IPA: [ˈmexiko] ( listen)), officially the United Mexican States (Spanish:  Estados Unidos Mexicanos (help·info)), is a federal constitutional republic in North America. It is bordered on the north by the United States of America; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of Mexico. Covering almost two million square kilometres (over 760,000 sq mi), Mexico is the fifth largest country in the Americas by total area and the thirteenth largest independent nation in the world. With an estimated population of over 113 million, it is the eleventh most populous country and the most populous Spanish-speaking country. Mexico is a federation comprising thirty-one states and a Federal District, the capital city.

In Pre-Columbian Mexico many cultures matured into advanced civilizations such as the Olmec, the Toltec, the Teotihuacan, the Zapotec, the Maya and the Aztec before the first contact with Europeans. In 1521, Spain conquered and colonized the territory from its base in México-Tenochtitlan, which was administered as the Viceroyalty of New Spain. This territory would eventually become Mexico as the colony's independence was recognized in 1821. The post-independence period was characterized by economic instability, the Mexican-American War and territorial cession to the United States, a civil war, two empires and a domestic dictatorship. The latter led to the Mexican Revolution in 1910, which culminated with the promulgation of the 1917 Constitution and the emergence of the country's current political system. Elections held in July 2000 marked the first time that an opposition party won the presidency from the Institutional Revolutionary Party.