A few months after founding this post Greig sold outto the U. S. Government and the post became known asthe "United States City Despatch Post." The governmentbegan operation of this purely local post on August 16,1842 under an Act of Congress of some years earlierwhich had authorized such local delivery.
The Act of Congress of March 3, 1845, effective July1, 1845, established uniform postal rates throughout thenation. But it was not until 1847 that Congress author-ized the general use of postage stamps.
Thus there were two gaps in the sequence of eventswhen no postage stamps were authorized by the govern-ment but during each of which postage stamps were, infact, being used by agencies of the government, i.e.:—