What is sometimes referred to as the first multicultural nation in the world? ​?

The appropriate response is the United States. The substance of multiculturalism is having unmistakable regions where individuals rehearse unexpected societies in comparison to the one general — if there is one by and large. For example, there may be a region where the prevailing religion isn't in control, or where individuals talk barely any English. 

In such manner, the US is a standout amongst the most multicultural nations I know. Individuals talk distinctive dialects in various ranges. English is talked by the larger part however Spanish is a reasonable second. On the off chance that you visit the Southeast or any piece of the nation along the Mexican fringe, you'll see this generally clearly.