United States Post Office Department

==1792–1829==
==1829–1837==
==1837–1971==
The United States Post Office Department was replaced with the United States Postal Service on July 1, 1971.
Category:United States federal executive departments
Category:Government agencies in the United States
Category:Postal services
Category:Mail
Category:Defunct
Category:Government
Category:United States
Category:1792
Category:1790s