Collected for philatelic interest, postal covers help document the development of post offices in Loudoun County. On 20 March 1793, the first post office opened in Leesburg. By 1830, twenty-five additional post offices were operating in Loudoun County and regular mail service was available. Postage could be pre-paid by the person sending a letter, or could be sent collect on delivery. Mail was franked by the postmaster when payment was received. In the United States, the first postage stamps were available in 1847, but not mandatory until 1856. In the interim, all methods of payment were acceptable and postage could be paid by sender or receiver.

Postal covers are the outside covering of a letter or an envelope with an address, postage stamps, or postal cancellation marks. A "stampless cover" is an envelope or folded outer sheet bearing an address and manuscript or ink-stamped postal markings, usually from the era before adhesive postage stamps. Later covers with cancelled adhesive stamps are also collected to document specific locations, post offices, or markings.

Although items in this collection were gathered for their postal interest, correspondence is included. A letter dated September 1836 from Wilson C. Seldon (1796-1843) to Henry Mason Morefit (1793-1865) requests payment of a settlement awarded to Seldon's Father. A December 1852 letter from William Powell (c.1817-1886) to Elie Beatty (1775-1859) confirms recipt of an earlier letter sent by Beatty in his role as cashier of the Hagerstown Bank. Both letters are postmarked Leesburg.

An envelope addressed to Leesburg Mayor John M. Orr (1820-1905) contains no correspondence, but does bear a handwritten 1866 postmark from Bolington, VA. Named after Daniel Boland (1792-1862), who established a farm, tavern, and store in the area, the post office was created in Bolington in 1836. Boland served as postmaster until 1862. During the American Civil War, the store was closed and portions of the farm burned. Isaiah Rinehart (fl.1839-1879) was appointed to replace Boland as postmaster in August 1865.