The U.S. Post Office is located at the intersection of Washington and George Streets in Charles Town. Some information about its history is provided below.
From Wikipedia:
In 1786, on 80 acres (320,000 m²) of his adjoining land, Charles laid out the streets of Charles Town, naming many of them after his brothers and one after his wife, Mildred. He donated the four corner lots at the intersection of George and Washington Streets for public buildings of the town and county, provided the town become the seat of the county separated from Berkeley County. Jefferson County was formed in 1801 as he anticipated. The county court house stands on one of these lots, as did the jail until 1919 when it was demolished to be replaced by the post office.
More detailed information is available from the City of Charles Town website:
In 1780 Charles Washington, George Washington's youngest brother, left his home in Fredericksburg, Virginia, and moved to the Lower Shenandoah Valley. Charles had inherited land in what was then Berkeley County, Virginia, from his older half-brother Lawrence.
In 1786 Charles petitioned the Virginia General Assembly for permission to incorporate a town. The petition was granted and Charles Town, Virginia was founded. In addition to naming the corporation for himself, Charles memorialized the Washington family by the naming of town's streets. The main street, running east to west is named Washington Street. Cross streets are named for family members with the Town Square named in honor of brother George, the streets to the east named for his bother Samuel and wife Mildred, and the streets to the west named for himself and his brother Lawrence. In a show of patriotism the streets parallel to Washington are named Congress and Liberty.
At the time of Charles' death in September 1799, Charles Town was still located in Berkeley County. In his will, Charles indicated that should Berkeley County be divided and Charles Town named county seat of a new county, he desired that the town lots on the town square formed by George and Washington Streets be used for public buildings.
Jefferson County was formed from Berkeley in 1801 and Charles Town became the new county seat. As the executor of his father's estate, Samuel Washington acceded to his father's wishes and deeded the Town Square to be used for public buildings.
In 1803 the Jefferson County Courthouse became the first public building to occupy the Town Square. This smaller brick structure was replaced by a larger courthouse in 1836. The 1836 courthouse was the setting for the trials of abolitionist John Brown and six of his followers. In October 1863, during the Civil War, the courthouse was heavily damaged by artillery fire rendering it unusable. Following the War the county seat was temporarily located in Shepherdstown. In 1871 the county seat returned to Charles Town and the courthouse was rebuilt.
The Jefferson County jail was the second public building to occupy the Town Square. Completed in 1806, perhaps its most famous occupants were abolitionist John Brown and six of his raiders. The seven men were housed in the Jefferson County jail from the time of their capture in October 1859 until they were executed.
During the Civil War, the jail was destroyed and was rebuilt in 1873 after the county seat returned to Charles Town. That building was torn down in 1919 and the jail was moved to the southeast corner of George and Liberty Streets. In 1920 the United States Post Office was constructed on the former jail site and has been there ever since.
Address:
101 W. Washington Street
Charles Town, WV 25414