How could the united states be described as a ‘melting pot’ at the end of the 19th and the beginning of the 20th century?

Because it had so many cultures from all around the world, migrating into the US

Just think, why was it effective? -it appeled to critics because it was written well, that made it noticeable to the public including the white population-it was also recognizable to the african americans because it was about their heritage.-it was powerful just keep finding more points and elaborate on them. message me if you need more