Three Northern Virginia sites -- Alexandria's 1775 Stabler-Leadbeater Apothecary, the 49-year-old George Washington Memorial Parkway to Mount Vernon and the 1854 Institute Farm in Loudoun County -- have been added to the Virginia Register of Historic Landmarks and nominated for the National Register of Historic Places.

The state register singles out places of exceptional historic merit worthy of preservation. It provides no protection for the sites, although inclusion on the national register gives limited protection against federally funded projects.

The Stabler-Leadbeater Apothecary, now a museum at 105-107 Fairfax Street in Old Town Alexandria, is among the oldest buildings of its kind in the country.

It was sold at public auction in 1933 and bought by the Landmarks Society of Alexandria. The apothecary, patronized by George Washington, George Mason, Henry Clay, John C. Calhoun and Daniel Webster, contains one of the nation's finest collections of antique drugstore furnishings and medicinal bottles, according to the Virginia Historic Landmarks Commission.

One of the apothecary's frequent visitors in the mid-1800s was Robert E. Lee, a good friend of John Leadbeater, son-in-law of founder Edward Stabler. One day in 1859, as Lee was chatting with friends in the shop, a young lieutenant, J. E. B. Stuart, hurried up to Lee, then a U.S. Army colonel, with orders from the commanding officer to advance immediately to Harpers Ferry to quell an insurrection by a man named John Brown.

The George Washington Memorial Parkway, originally called the Mount Vernon Memorial Highway, was first planned in 1887 as a parkway "of noble proportions" linking Washington and Mount Vernon. However, the plans were shelved in 1892 when a privately owned electric trolley to Mount Vernon was built along most of the route for the proposed parkway.

In 1922, when Arlington Memorial Bridge was approved by Congress, the parkway idea was revived and planned to open in 1932 as a tribute to Washington on the 200th anniversary of his birth. The trolley line, succumbing to the Depression and the advent of the automobile, was expropriated and the parkway followed much of its route.

Under the 1930 Capper-Crampton Act, the federal government proposed creating a George Washington Memorial Parkway on both sides of the Potomac.

Virginia residents, however, blocked extension of the parkway beyond the Beltway, and in Maryland, only a short portion was built past the Beltway between Chain Bridge and Carderock.

The Institute Farm near Aldie in Loudoun County was the first agricultural school in Virginia and one of the nation's first schools of scientific agronomy.

Once part of President James Monroe's Oak Hill, the farm has been the headquarters of the National Beagle Club of American since 1916.

The institute was founded in 1854 by the Loudoun County Agricultural Institute and Chemical Academy, and was the site of pioneer work in deep plowing and crop rotation, then virtually unknown in the rural South. "Despite its forward-looking character," the Landmarks Commission notes, the institute folded only six years later on the eve of the Civil War. n