So with a little research (I used the statistical atlas linked below) I found that in the state of Florida, for example, 15 zip codes are 100% white (non-Hispanics), and 30 zip codes are 100% black (including black Hispanics)
A person shopping for a house or condo may find that a realtor will not answer questions about the racial composition of neighborhoods. Although the federal government publishes detailed census data on racial composition, updated every 10 years, realtors (and the state commissions that regulate their conduct) consider it unethical to talk about it.