Jesus showed compassion for all and helped them: the poor, the despised, the outcasts, and wants us to do the same (Matt. 4:24-25;9:9-13).
The Christian life is marked by baptism (Matt. 3:13-17).
So that everyone knew there were Jewish I think
The main factor that influenced African Americans to migrate from the South to Northern cities was that they were looking for better economic opportunities.
The Great Migration, also known as the Great Northward Migration in the 20th century, happened because most black people were badly treated by many people that still expected African Americans to be slaves, and their economic conditions were quite poor.
As a result, African Americans decided to migrate to the Northern cities, where they would get many job opportunities as well as going to have a better lifestyle by not being discriminated.