United Republic of North America
From Halopedia, the Halo wiki
The United Republic of North America is an organization located in the continent of North America on Earth [1].
Possible Unions
The United Republic of North America could consist of a union between the United States, Canada or any other nation situated in the proximity of North America, such as Mexico or Cuba. However, this theory is yet to be confirmed by Bungie. It may be that it is a descendant of the, currently theoretical, North American Union.