Someone might be able to be more helpful if the original poster would be more specific as to his interest.
What state or region is of interest?
As
paperhistory noted, there are some compilations of this type available. Virtually all are based on a state or county and not US in general.
The following link is to a project I started a while back. It is incomplete and some links are broken, but it might have some useful information. Although identified as a Stamp Smarter project, it is not currently available from the Stamp Smarter website as it is still "under development".
https://stampsmarter.org/Learning/LinksPortal.htmlMike