I am really interested in this. Could you provide some links, please?
There were also redlining practices and things like razing and redeveloping the predominantly black Fillmore making it a neighborhood the previous residents could no longer afford.
https://www.epi.org/publication/the-color-of-law-a-forgotten...
Long story short:
Richmond grew during WWII because it was a large ship building yard for the pacific fleet. Lots of white and black people moved to Richmond from the South and East during this time. After the war, the ship building stopped, and the workers needed to get new jobs. There was a large auto plant that opened up in Milpitas (near San Jose), that hired a lot of the workers, both black and white. There were a lot of "whites only" suburbs built near the Milpitas plant and a lot of the white ship workers moved there, bought houses, had short commutes to work, and built wealth through housing appreciation. As white folks left the Richmond community and black folks remained, the lack of political power held by black folks at the time (Jim Crow laws, discrimination, etc) lead to disinvestment in the richmond community (poorer schools, roads didn't get repaired, leading to lower property values etc). The disinvestment and community decline made it more difficult for the black community to move away, because they didn't have any housing wealth compared to neighboring communities (and many communities at the time were "white only"). Additionally, the black workers commuting to Milpitas to work spent 2.5 hrs/day commuting, while the white workers spent like 15 minutes, so thats 2 hours and 15 minutes every day for 25 years that white fathers could spend at home teaching their kids to read/focusing on their education, improving their house, building social connections/capital etc that the black fathers didn't have. That impact on the next generation compounds over time and makes a material impact on the potential of the next generation.
"Many communities were white only" is a crock; in fact, Milpitas in the 1970s had higher black propensity than did Fremont to the north or NE San Jose to the south. Both Milpitas and Ayer High schools had more black students than Piedmont Hills to the south. The foothills tended to be pricey and almost exclusively white and Jewish, but that was economic rather than code segregation.
By the 1970s, production at the plant spiraled downward, shifts were cut, abd there were always more workers than hours.