Across the Potomac River from the nation's capital, Arlington occupies a site rich in history. The Arlington Historical Society founded in 1956, is a nonprofit organization formed to preserve the area's history and present it to the public.

With more than 350,000 donated artifacts -- displayed on a rotating basis -- the society does just that in two historical landmarks it owns and operates. Constructed in 1891, the Arlington Historical Museum is a little red-brick building with a bell tower, the oldest existing schoolhouse in Arlington.

The Ball-Setters House, built of logs in 1750, is the county's oldest standing structure. Both buildings are listed as Virginia State Historical Landmarks on the National Register of Historic Sites.

Exhibits in these time capsules weave thousands of years back and forth. About 12,000 years ago, Native Americans occupied more than a dozen sites in Arlington. In 1608, the first recorded encounter occurred between Capt. John Smith and a tribe referred to as Nocostins, who spoke an Algonquian dialect. The site of the tribe's village was Analostan Island (now Theodore Roosevelt Island). Colonial settlers soon followed Captain Smith's arrival.

Later, George Washington, George Mason and other revolutionary leaders called Northern Virginia home. For 45 years -- 1801 to 1846 -- Arlington was part of the nation's capital until the federal government approved the return of the county to Virginia.

During the Civil War, Arlington County was transformed as 100,000 Union troops were stationed at 22 forts and other encampments to defend the federal capital from Confederate attacks. Arlington linked North and South strategically via two arteries: Aqueduct Bridge (now Key Bridge) and the Long Bridge (now 14th Street Bridge), the critical railroad crossing.

In 1863, newly emancipated slaves found safety in Freedman's Village in Arlington Heights, which had more than 100 homes and larger structures. Aspects of this village are re-created in an exhibit at the museum.

-- Jennifer Mar