In the 1900s, banks and the government used redlining with color-coded maps to keep Black and immigrant families from buying homes in certain areas. They marked neighborhoods with many Black or immigrant families as "risky" and refused to give loans there.
Today, we see gentrification changing neighborhoods through money and business - fancy apartments, hip coffee shops, and much higher rent prices. One was done by the government, the other by businesses looking to make money. But both push out the people who lived there first.
When new, richer people move in, the old shops close down, rent gets too high, and longtime residents have to move away. Both systems end up moving out the same groups of people who were just trying to build a stable life.