Answer:
He is describing how immigrants from around the world coming together will eventually form a unique hybrid and culture of it's own. He believed America is completely unique because of this diversity and it would help the country grow and prosper, having a demographic of people no other country had. Many different perspectives and ways of life can only improve a society.
Step-by-step explanation:
America is often called a "melting-pot" because many culturally different people come together and form something completely new.