Answer: Agricultural Hearths. When looking at the spread of new ideas, we start with the place where that idea emerged. We call this a hearth, so an agricultural hearth would be the place where farming was first developed. Over in China, between the Yellow and Yangtze rivers, ancient people developed agriculture on their own.
This means that public services such as bathrooms or water fountains could still be whites only or blacks only but they had to be equal in quality. (i.e the bathroom for whites only could not be very clean and fancy while the blacks only bathroom was dirty).
