There was one comment under the Home Depot thread about nation names that needs clarification.
One comment was that there are several United States of .............. That isn't true as far as I can tell. There are only two.
There is The United States of American and the Estados Unidos Mexicanos which can be translated as the United States of Mexico, but is more often written the United Mexican States. Thus the abbreviations in English are the USA and UMS or in Spanish the EUM.
The common shortening of USA is America (thus the citizens (nationals) are know as Americans) and the common shortening of the EUM is Mexico and the nationals are know as Mexicanos.
Brazil, unless it has changed in the last year or so is the Republica Federativa do Brasil or in English the Federative Republic of Brazil.