Retired naval commander and defense history buff Philip Erickson of Alexandria was taking a stroll on Jones Point one day last summer when he realized that a mound of earth there formed part of a fortress built in the late 1700s to protect the then-young port city.

Erickson, 60, began paging through early American books at the National Archives, Smithsonian Institution, Army Corps of Engineers, Library of Congress and other libraries, searching for documents to confirm his suspicion.

"I'm a historian. I love the City of Alexandria, and I want to make sure that all of the history of Alexandria can be surfaced and presented to the American people," Erickson said during a recent interview.

"What we are trying to do is recreate the city and make it a living historical city," Erickson said.

Erickson found what he was looking for about the fortress in the first volume of the American State Papers, in a letter dated May 12, 1794, and written by Secretary of War Henry Knox to John Vermonnet, a French engineer.

Knox gave orders to construct a fortress at Jones Point on a $3,000 budget.

Later correspondence between Knox and Vermonnet mentioned a plan to arm the fortress with 12 cannon, but Erickson said that he could imagine no more than four muzzle-loading cannon ever defending the shores of Alexandria from British ships. The cannon could fire shots 1,000 yards, which Erickson says was a good distance for the time.

Erickson, a volunteer member of the city's Archeology Research Center, now wants to use metal detectors to search for cannon balls, muskets and other relics of early American warfare that may be buried at the fortress site on Jones Point, a 50-acre federal park south of Old Town Alexandria. He said he hopes the center can persuade the City Council to supply the money to look, and perhaps to dig, for relics of those early days.

Alexandria archeologist Pamela Cressey, who works at the center, said the center must finish mapping the terrain of Jones Point before it can approach the Interior Department's National Park Service, which owns Jones Point, about excavating the land.

Alexandria merchants and patriots constructed the fortress at Jones Point to protect their property and city--then the fifth largest port in the states--from British invasion, Erickson said. The L-shaped fortress was equipped with mobile cannon that could not only do battle with British ships as they made their way up the Potomac but could reposition to attack any ships that might escape the fire. Behind the earthen fortress there were two bastions where soldiers and supplies were sheltered.

Just southwest of Jones Point, at Great Hunting Creek, two ships propelled by oars and sails would hide in the swamp awaiting enemy ships, according to Erickson's research.

By 1804, the fortress had seen no warfare and was beginning to decay. Congress decided it could no longer afford to maintain it and it was abandoned.