Every hour it used to appear, this ghost from the past. A curtain would fall to reveal it, filling an entire wall of the National Museum of American History's great lobby at the Mall entrance. It was, of course, the huge American flag that flew over Baltimore's Fort McHenry on a hot summer night in 1814. "Was," because this object at hand, the original Star-Spangled Banner, is no longer "still there." The effects of age brought it down — something the British failed to do 186 years ago.

That giant flag, one of the Smithsonian's proudest treasures, is being cleaned and perked up in a large room about 150 feet away, and you can see it happening. Look into the conservation lab, and there's the old flag stretched out as though waiting for the surgeon to scrub up. But it's a team of conservators who do the operating here, sitting beside the fragile fabric, inching carefully around it, examining every flaw. They'll finish in 2002, they say.

An exhibition along the concourse offers enough background to challenge many notions you may have cherished about the glories of the War of 1812. One episode that's hard to forget, much as we'd like to, is the sack of our national capital in 1814. A British landing force put ashore from the Chesapeake Bay, marched inland in the humid heat of August and headed for "Washington City." We scraped up all the militia we could, and ventured to meet the invaders at the suburb of Bladensburg. At first glimpse of approaching redcoats with bayonets aglitter, most of us scampered home as fast as our weary legs could take us. The battle became known as the Bladensburg Races.

The British were tired too, but they pressed on to Washington, burned the Capitol and many other buildings, and stormed into the White House. Before setting it ablaze, the officers sat down to a sumptuous dinner laid out for President and Mrs. James Madison, who had hastily departed, Dolly Madison clutching Gilbert Stuart's portrait of George Washington.

Though the war was hardly our finest hour, it did have its moments, and that's where the flag now at the Smithsonian made its bow. Leaving Washington smoking, the British troops, flushed with success (and wine), marched toward the Bay to rejoin their fleet and attack the vital seaport of Baltimore. We Americans, humbled but angry, finally rose to the occasion. Capable leaders appeared and strengthened Baltimore's defenses, beefing up Fort McHenry, which guarded the harbor, adding shore batteries. More militia arrived from Pennsylvania and Virginia, and a regiment of regulars showed up.

Earlier, in the second year of the war, Fort McHenry's new commander, Maj. George Armistead, had asked for a suitable flag to fly above it, "so large that the British will have no difficulty in seeing it from a distance." The request was granted, and Mary Pickersgill, who supplemented her widow's mite by making flags for Baltimore ships, started fabricating a standard-sized garrison flag — 42 by 30 feet, with 15 stars stretching 26 inches across and two-foot stripes — 15 of them, since the number of stripes didn't revert to the original 13 until 1818.

Now the British were really coming. Glutted with victory, and dead tired, they encamped at Upper Marlborough. On the way to Washington, they'd usurped the manor house of Dr. William Beanes, a feisty 65-year-old, eminent in his profession. Now, as the British reached town again, roistering redcoats disturbed Beanes and his dinner guests. They went out to stop the noise and got the drunk soldiers jailed. For this, the British brass ordered that Beanes be taken prisoner.

Aghast, the doctor's friends set about trying to get him released. A parley with the British command called for a skillful negotiator, able to exert charm yet put generals and admirals firmly in their place...Aha! Francis Scott Key!

Key was one of those people who knew everybody. By 1814, he was a lawyer and a popular success, with a wealthy wife and a fine home in Georgetown, the rich old neighbor of muddy little Washington. He liked to scribble poetry — a not unusual diversion two centuries ago. He was a godly man, a pacifist who hated this war yet served as an officer in a Georgetown artillery company. Altogether, this able, likable, well-connected dilettante was the perfect choice for an extremely dicey — if not impossible — mission.

Letters were exchanged across the battle lines. Grudgingly, the British agreed to let Key and Col. John Skinner, in charge of prisoner exchange, make their plea if they could meet the British fleet, sailing up the Chesapeake. Key and Skinner hailed the British flagship from their small vessel, were taken aboard and learned that Beanes was in danger of being hanged. Key went to work, pointing out that the doctor had treated wounded British soldiers with the same care and kindness as he had Americans. That won over the British command. Dr. Beanes could go, but he and his rescuers must stay with the fleet until Baltimore went the way of Washington. Under a guard of marines, Key's party ended up in their vessel, towed by the British flagship as it surged up the Bay.

On September 11, the British fleet came together — 50 vessels, ranging from the 80-gun flagship through 74-gun men-of-war, 38- and 36-gun frigates, to rocket and bomb ships (actually huge rafts). Transports carried "Wellington's Invincibles," the 4,000 or so troops who had so enjoyed themselves in Washington.

Early on the morning of the 12th, the redcoats landed east of Baltimore and charged the massed militia. And this time things fell apart for the British. Two American snipers quickly picked off the British commanding general, and although some militiamen skedaddled, many others stuck it out. Humid, rainy weather helped the American cause. The Invincibles pulled back and encamped, waiting for the navy to do its stuff. The ships would first have to put out of action that pesky Fort McHenry.

Next morning, in pouring rain, bomb ships opened fire thunderously from about two miles below Fort McHenry — well out of range of its guns. Mortar bombs, some of 200 pounds, soared high in the air and plunged into the fort to explode in showers of rubble. Key, Skinner and Beanes had a distant view from their small vessel. They made out a flag, limp in the soggy air.

All day the guns bellowed. Newly introduced Congreve rockets screeched toward the fort in hopes of starting fires. When enemy "bomb," or mortar, vessels moved in to score even more hits, the Americans opened up with everything they had and drove the British back.

Night fell. The tremendous bombardment eased off as boatloads of British troops slipped past the fort to attack the city. The Americans spotted the foray, and their guns roared, and again the British had to pull out of range. Desperate to finish off the fort, they redoubled their cannonade, bombs curling high in the night sky, their lit fuses streaking across it, then down to their bright burst. Key, tirelessly watching, realized that the roar of British guns meant the fort still held; by the burst of bombs he could see the flag, still there.

And, in the faintest first light of dawn, at about the time the British command called off its Baltimore campaign, he spotted it. The rain had ceased; a stirring of wind opened it, and he made out the red of the stripes, the blue square. The American flag.

As a poet, Key could be suddenly and deeply moved, and instinctively he'd create rhythmic phrases to describe his feelings. All night, words had tumbled in his head: proudly hailed...gallantly streaming...bombs bursting in air...gave proof...Still there! Now he scribbled them on the back of a letter, then later, safely ashore in Baltimore, he wrote out and polished the song. Of course it had to be a song.

The phrasing of "Defence of Fort McHenry," as he first named it, fitted perfectly an old favorite: "To Anacreon in Heaven." This was the song of a popular London gentlemen's club, the Anacreontic Society, honoring an ancient Greek poet who lyricized life's joys. Members devoted themselves to good food, good wine, good cheer. They'd composed a pleasant, lilting tune, and one of the club's presidents had supplied words, a fanciful communication with Anacreon, fun to sing:

To Anacreon, in Heav'n, where he sat in full glee,
A few sons of harmony sent a petition,
That he their inspirer and patron would be;
When this answer arriv'd from the jolly old Grecian—
"Voice, fiddle, and flute,
No longer be mute;
I'll lend ye my name, and inspire ye to boot;
And, besides, I'll instruct ye, like me to intwine
The myrtle of Venus with Bacchus's vine."

The music was a hit in America. A patriotic song, "Adams and Liberty" (later changed to "Jefferson and Liberty"), adopted the tune, which was also used for a song celebrating the naval war against Barbary pirates, early in the 19th century: "When the warrior returns, from the battle afar, To the home and the country he nobly defended...." And who had written that? Francis Scott Key.

"The Star-Spangled Banner" was popular, but not our national anthem. Not until 1931 did Congress grant that status. Before that we'd made do with "My Country 'Tis Of Thee," our version of "God Save the King (Queen)" as an anthem. (Many people still regret that "America the Beautiful" wasn't chosen.) But Key's song, played more slowly than the original song, with a few crashing chords and drumrolls, works well because it deals with our flag. We Americans don't have a king or queen. We have a flag.

The Smithsonian got this one in 1907, as a loan from Armistead's grandson that turned into a gift. A strange red V may have been the start of an A for Armistead. Some missing pieces were probably snipped out for souvenirs. They were likely not shot away during the bombardment. In that rain, the flag would have drooped against its mast with little chance of being hit.

In fact, some experts believe that the giant Pickersgill flag wasn't raised at all until that clear morning when Key saw it; another banner had flown in the rain. The impact on Key as the morning breeze finally revealed the enormous emblem of his beloved country — beaten, scoffed at, but still in the fight — must have been explosive.

Even in these cynical days, Americans who have lived abroad for a while, and suddenly meet the Stars and Stripes, feel a wrenching emotional surge — the pulse quickens, breath shortens, the throat tightens. In Alice Duer Miller's narrative poem "The White Cliffs," an American girl, living in England during World War I, feels Britain's anger and dismay at our continued neutrality during three years of suffering. Then the American doughboys arrive on their way to the trenches:

Marching through London to the beat of a boastful air,
Seeing for the first time Piccadilly and Leicester Square,
All the bands playing: "Over There, Over There,
Send the word, send the word to beware - "
And as the American flag went fluttering by,
Englishmen uncovered, and I began to cry.

By Edwards Park