The datum is defined by the observed heights of mean sea level at the 26 tide gauges and by the set of elevations of all bench marks resulting from the adjustment. A total of 106,724 kilometers of leveling was involved, constituting 246 closed circuits and 25 circuits at sea level.
George Washingtonâs Mount Vernon is located roughly 15 miles south of Washington, D.C. and 8 miles south of Alexandria, Virginia on the banks of the Potomac River, at the southern end of the George Washington Memorial Parkway.
Mount Vernon. Mount Vernon, NE Va., overlooking the Potomac River near Alexandria, S of Washington, D.C.; home of George Washington from 1747 until his death in 1799.The land was patented in 1674, and the house was built in 1743 by Lawrence Washington, George Washington's half-brother.Mount Vernon was named for Admiral Edward Vernon, Lawrence's commander in the British navy.ount Vernon. Mount Vernon, NE Va., overlooking the Potomac River near Alexandria, S of Washington, D.C.; home of George Washington from 1747 until his death in 1799.