Mexico
From Halopedia, the Halo wiki
Mexico is a country on Earth located in the North American continent. Its capital is Mexico City. It is bordered by the United States to the north.
United Republic of North America
Mexico is a part of the United Republic of North America, a loose association with the nations of Canada and the United States of America.
UNSC
It was the location of Base Segundo Terra, a major facility for the UNSC and UNSCDF in the region.[1]
Human-Covenant War
In 2552, during the Battle of Earth, SPARTAN-104, SPARTAN-058 and SPARTAN-043 used the Base Segundo Terra as a staging point to attack the Covenant incursions on Havana.[2]