The main change is the countries the immigrants were coming from. The immigrants in 1840s were coming from the Western Europe mainly Ireland and Germany. Immigrants from Asia and Eastern Europe were coming a bit later while during the beginning of the 20th century most of the immigrants came from Italy.
Brown v. Board of Education is important because it marked an important victory in the struggle for racial equality.
Repetition because he repeats the word we more than 3 times. He is stating that we as a community need to work together and not individually
I hope this helped!!