There's another part of the story of Fort McHenry, one that is not much concerned with the War of 1812 and the bombing that inspired "The Star-Spangled Banner."
Scott Sheads, 42, the national shrine's historian, has spent the past several years detailing Fort McHenry's use during the Civil War when it was a federal prison.
Fort McHenry was the military headquarters of Baltimore, the keystone of the Eighth Army Corps, an installation and prison where some 2,000 political prisoners were jailed at times during this period of conflict and division. Of that number, 28 were newspapermen and 31 were members of the Maryland General Assembly who sympathized with the Confederacy.
"At that time you could be arrested if you rode a horse up Charles Street, waved your hat and shouted, 'Three cheers for Jefferson Davis!' " Sheads says.
Generations of Baltimoreans tend to associate Fort McHenry with the big black cannon along a parapet and pointed over the harbor. The historian has documented that in the 1860s there were a pair of 10-inch Columbiads aimed not at ships in the Patapsco River, but at the Washington Monument in the heart of the affluent Mount Vernon neighborhood.
Similar cannon were mounted at the Union encampment on Fort Federal Hill and aimed at the Pratt Street business district.
"I've tracked down these cannon. One survives in the town square of Willoughby, Ohio," Sheads says. Willoughby is east of Cleveland, just off Lake Erie.
Much of his research will be used for a Civil War encampment re-enactment planned April 23-24 at Fort McHenry. The event, which includes torchlight tours of the old citadel, will focus on civilian and garrison life some 130 years ago.
Sheads notes there were 42 forts and camps established around Baltimore to form a protective circle around a city of major strategic importance to the federal government. Of all these military posts only Fort McHenry survived.
"In the traditional Civil War histories, Antietam and Gettysburg have always overshadowed Baltimore," he says. "But Baltimore played a greater role than people realize. It was a crucial spot in the first two years of the war because of communications. Telegraph lines and railroads from the north and west came through Baltimore and then on to the nation's capital.
"Baltimore was a Southern city and had to be held at all costs. People today don't always realize the extent of the federal presence. A battle need not have taken place for a spot to be important."
There were at least three military executions at the fort during the Civil War. In March 1862, a firing squad took aim at Joseph Kunhe, who had murdered an officer he did not like.
The fort saw distinguished visitors -- including Gen. George B. McClellan, Secretary of State William Seward (best known for negotiating the purchase of Alaska) and the Glasgow-born detective Allan Pinkerton -- and some not so distinguished visitors.
Fort McHenry was home briefly to some 2,000 Confederate soldiers captured at Antietam and 8,000 at Gettysburg. They arrived on the Baltimore and Ohio and Northern Central railroads and marched from Camden and Calvert stations to the fort. Many stayed only a week or so before being sent to Fort Delaware (Pea Patch Island) in the Delaware River or to the prisoner exchange center at Fort Monroe, Va.
In his research, Sheads read Baltimore's daily newspapers, especially the Baltimore American and The Sun, but much of his information was culled from a register that bore the handwritten title, "Guard's Record at Fort McHenry."
"The comments in this book make some of the best reading. In 1863, the sisters Marie and Eda Coe were captured as rebel mail carriers. They were brought into the fort and the comment written in the book, 'They are desperate and dangerous women . . . and must be carefully watched at all times.' "
So if Fort McHenry was a kind of local Civil War-era Alcatraz, did anyone slip out? There were 38 recorded escapes, Sheads says, adding, "You bribed the guard and off you went."
Those who couldn't pay bribes played a game that Sheads conjectures was baseball.
"On the weekend of April 23, we'll be playing baseball here using the official 1861 book of regulations," he says.