Columbia subject headings:
Post roads--United States--Statistics.
Postal service--United States--Statistics.
United States. Post Office Department--Appropriations and expenditures.
Harvard subject headings:
Post roads--United States--Statistics.
Postal service--United States--Statistics.
United States. General Post Office--Appropriations and expenditures.
Princeton subject headings:
Post roads--United States--Statistics.
Postal service--United States--Statistics.
United States. Post Office Department--Appropriations and expenditures.