Thank you for posting your request on History Hub.
In regards to your question, R.F.D. 1, Washington, Washington, PA is not a personal or business address. The R.F.D. stands for Rural Free Delivery, Route Number 1, in Washington PA. At the time when the R.F.D system was in place, mail carriers would be assigned a route, much as they are today, and they would be required to have a list of the names all of the families on that route. Houses/mail boxes were not numbered, but were, instead marked with the name of the family or families living at the location. The mail carrier was then responsible for completing their route and delivering the mail to the house by family name.
So, as an Example,
R.F.D. 1 Washington
would simply tell the carrier whose route was R.F.D. 1 to drop a letter off at John Doe's house as they completed their route.
I have located a few interesting pages that discuss the R.F.D. system which you might find informative.
I could not find a listing of equivalent routes between the old R.F.D system and today, but you may wish to investigate some of the resources the USPS Historian's Office lists here, to see if such a cross-reference exists.
I hope this is helpful in your research.
Welcome to History Hub
You could try the Washington County Land Records.
If that doesn't work try, obituaries, death notices, birth records, census records.
familysearch.org is a free website you just need to join to research family histories.
Would you like to share the family names that you are researching?
The family name is
Ralph Bluebaugh and Margaret Edith Cullen. They were my great aunt and uncle. They lived out in the country on a small farm and Ralph grew roses and fruit trees on the weekends when he wasn't being the superintendent of the local school district. My sister and I are doing a family trip back to visit old gravesites and would love to find their house and/or property. Every piece of information I have states only the RD 1 Washington, Washington Co Pa.
If only I could find online a map of the Rural Delivery Routes.
Appreciate all your help.