The United States has been known as "___" meaning that people of all races and nationalities are welcome into its borders.

The United States has been known as "the great melting pot", meaning that people of all races and nationalities are welcome into its borders. This name is a metaphor for the many cultures, languages, and religions found in the country. It also shows that the country is a place that respects and appreciates the varying races and cultures of its people.