WWII brought labor shortages and drew thousands of people from all over the country to the Bay Area. Despite these shortages, discrimination still reigned, both in the war-critical shipyards and in everyday businesses.
Black people were directed to less skilled, lower paying jobs, given second tier union representation, and as in Port Chicago, often given the most dangerous assignments.
Businesses like Union Pacific Laundry were forced to adapt by hiring people of color and women when previously they hired only white men. This didn’t translate into equal pay and treatment, but it was a start.
Of interest nearby: