Despite an earlier raid that was repulsed by American militia, the more than 4,000-man British force faced no resistance on Aug. 19 as it swarmed ashore in Southern Maryland. Four days later, after defeating disorganized American defenses at Bladensburg, the soldiers marched into Washington unopposed, setting fire to the Capitol and White House and demoralizing the nation.
"It's the only time the nation's capital was ever occupied by a foreign power and this is where it started," said Eshelman, who has co-written a new book about the War of 1812 in the Chesapeake Bay region to be published next month. "There was no actual conflict, but this is a very, very important site."
And like many historic sites from the nation's second war with the British, it is once again in danger of being overrun.
Because much of the land where the soldiers encamped is privately held, the fields west of Benedict make up one of seven historic War of 1812 sites in Maryland the U.S. Department of Interior considers threatened by development in the next decade, according to a 2008 report.
Nationwide, 164 battlefields and historic sites from the War of 1812 and the American Revolution face "medium" or "high" risk of destruction by 2018.
More than 100 historic locations along the East Coast are already gone.
Since 1996, federal authorities have focused preservation efforts on Civil War sites such as the Antietam National Battlefield in Western Maryland, where Gen. Robert E. Lee's confederate soldiers clashed with the Union Army in a battle that left 3,650 dead.
Far fewer federal resources have been directed to preserve similar sites from the War of 1812, which will be remembered in a series of bicentennial events this year.
A bipartisan bill advancing in Congress could change that. The proposal, approved unanimously by the House Committee on Natural Resources last month, would expand the American Battlefield Protection Program beyond Civil War sites to include properties that played a role in the American Revolution and the War of 1812.
The measure authorizes $10 million in grants that local governments would match to buy historic properties for preservation.
As lawmakers work to reduce federal budget deficits, any new spending faces shaky prospects in Congress. But the bill, crafted by Democratic Rep. Rush Holt of New Jersey, has two Republican co-sponsors and could receive a vote by the full House in coming weeks.
"History is best experienced by those who can touch it and feel it," Holt said during a hearing earlier this year. "There is really a desperate need to act and to act quickly."
The Senate version of the bill is sponsored by Sen. Charles Schumer, a New York Democrat.
Historians say changes to the way the federal government approaches the sites are long overdue.
"It is surprising how little attention is given to the sites from the Revolution and the War of 1812," said Thomas J. Cassidy Jr., a lobbyist with the National Trust for Historic Preservation. "There are very few protected sites associated with that enormously significant period."
Other sites at risk in Maryland include several fields in Queen Anne's County where a small American militia held off a British force of 300 in the 1813 Battle of Slippery Hill. The Department of the Interior list also includes Caulk's Field, a Kent County battlefield that experts believe is the best-preserved War of 1812 site in the state.
The British engaged with Benedict in an unopposed raid and a later skirmish before landing there in 1814 to launch their attack, Eshelman said. The skirmish involved Francis Scott Key, who would later write the lyrics that became the Star-Spangled Banner. Key was on a scouting mission in the region when the British ships approached Benedict.
In August 1814, a British force led by Gen. Robert Ross sailed up the Patuxent to Benedict. The water's depth allowed the ships to move upriver easily and the area's well-maintained roads provided good access to Washington.