![O56P1 - 1873 90c Official Mail Stamp - Post Office, black, O56P1 - 1873 90c Official Mail Stamp - Post Office, black,](https://cdn11.bigcommerce.com/s-9xwo1raw7u/images/stencil/500x659/products/62971/46380/USA-O56P1__73393.1711072249.jpg?c=1)
1873 90c Official Mail Stamp -post office, black
# O56P4 - 1873 90c Official Mail Stamp -post office, black
$8.00 - $12.50
Official Mail Stamps- Missing From Many Collections
Official Mail stamps, also known as departmental stamps, were developed in the 19th century as a means of accounting for postage on mail sent by various federal departments. These are a neat area of philately, and would make a great addition to your U.S. collection.
Official Mail Stamps- Missing From Many Collections
Official Mail stamps, also known as departmental stamps, were developed in the 19th century as a means of accounting for postage on mail sent by various federal departments. These are a neat area of philately, and would make a great addition to your U.S. collection.