More than 200 years ago, lawyer Francis Scott Key, advocating for a client, was detained aboard a British warship in Baltimore Harbor and became a witness to history. As the Battle of Baltimore raged around him in September 1814, he wrote down the words that would become the national anthem for the United States. The story of the song, and the flag that inspired it, is the subject of the Smithsonian Channel documentary "A Star-Spangled Story: Battle For America."

Rich in historical detail and information about the anthem and the banner itself, the special commemorates this important anniversary with interviews, reenactments, 3-D computer graphics and artifacts from the Smithsonian. The special first aired in June 2014, but you can catch it this month and next on the Smithsonian Channel.

Executive producer Tim Evans shared his insights about why the story is so compelling.

MNN: In comparison to other conflicts, why don't we know that much about the War of 1812, other than that Key wrote the song then?

Tim Evans: I think it’s a problem of "branding." "The War of 1812" is a terrible name, and it doesn't have the impact of a name like "The Civil War" or "World War II." The name is also inaccurate, since the worst part took place in 1814, not 1812. Finally, the stakes of the war were not very clear — either back then or now. The war began when America took offense at having its citizens arrested and forced to work on British naval ships. No one thought at the beginning that it would result in three years of war, an invasion, the destruction of the capital, and the near-destruction of America. And no one really remembers that now. Hopefully, "A Star-Spangled Story: Battle for America" will change public perception, and remind viewers how the 200th anniversary of the national anthem has vital importance for today.

What is the historical significance/importance of it? What would have happened if America lost?

If America had lost the War of 1812, the nation as we know it would not exist now. In the summer of 1814, British troops attacked the capital and burned it to the ground. They planned to attack and conquer Baltimore, New York and New Orleans in short order after that. An American defeat would mean the British Empire would control everything West of the Mississippi from 1815 onward. There would be no American West. The California Gold Rush would fill British coffers, not American. Americans would never sing "from sea to shining sea." At best, America would be a poverty-stricken country incapable of growth. At worst, it would become another colony of the British Empire.

Why was Washington, D.C., so vulnerable?

Washington was vulnerable for two reasons. In the first place, the main body of the Army was far away, in an ill-conceived attack on Canada. In the second place, the Washington insiders refused to believe that the British would attack. Hence, the capital was simply unable to defend itself once Redcoats showed up.

We were losing ... so what turned it around?

I think the American citizenry turned it around. It certainly wasn't the American military. The American troops ran away so fast from their first encounter with British troops outside Washington that they called it The Bladensburg Races. But after the burning of Washington, D.C., the citizens of Baltimore banded together. They dug trenches around the city, they sunk numerous ships in the harbor to prevent a seaside attack, and they simply withstood a brutal two-pronged attack long enough for the British to give up and back off. A similar situation happened in New Orleans a year later. When the Redcoats showed up, an Indian-fighter named Andrew Jackson teamed up with a pirate named Jean Lafitte. They pulled together a militia and regular troops and withstood a prolonged British assault. The British Empire boasted the best Navy and the best Army in the world — having just defeated Napoleon. But I think they simply didn't count on Americans and their willingness to hang on and refuse to fight by the traditional European ground rules.

Why has this particular flag become such an enduring symbol? How fragile is the condition it's in now, and what steps are being taken to preserve it?

The flag that Francis Scott Key wrote about — the literal "Star-Spangled Banner" — is about as perfectly preserved as a 200-year-old war relic can be. It hung in the Smithsonian's Great Hall for decades, which was probably one of the worst ways to preserve it, since it was exposed to air, light, moisture, mold and pollution. In 1998, the Smithsonian took it down and began an eight-year preservation process: cleaning it, examining it and building a protective location for it. The flag now rests in a chamber that is oxygen-free to prevent fire, and it lies on a nearly flat surface with very low lighting to prevent any further damage. The great thing is that the chamber is lit so dramatically and it's built with the public in mind, so that 1.8 million Americans every year can visit and witness this extraordinary artifact that sums up so much of what our nation means.

preservationists Jennifer Jones and Suzanne Thomassen-Krauss inspect the Key's star-spangled banner

Preservationists Jennifer Jones (left) and Suzanne Thomassen-Krauss inspect the flag that inspired Francis Scott Key to write 'The Star-Spangled Banner.' (Photo: Smithsonian Institute)

What do you make of the song's history as a drinking song?

The tune for "The Star-Spangled Banner" was a drinking song, but not the kind of song you might hear in a raucous bar. It was written in the 1760s for a gentleman's drinking club — essentially a high-end club for wealthy and educated Englishman to hang out and drink. The tune "To Anacreon In Heaven" is really hard to sing, covering an octave and a half, and that was on purpose. The song was designed so the club's members could show off their singing abilities. Francis Scott Key knew the song and apparently had it in the back of his mind when creating the poem. I don't think he realized what a problem the tune would be when every person in America is expected to be able to sing it before a baseball game.

There was talk of changing the anthem to something easier to sing, such as 'God Bless America' or 'America the Beautiful.' Are you glad it wasn't?

By the time the other patriotic candidates for a national anthem were written, it was really too late. Americans had already considered "The Star-Spangled Banner" to be the nation's song, and the official declaration in 1931 only confirmed a given fact. Michael Dean, a UCLA professor and vocal coach, was one of our interviewees, and I think he said it best. "'The Star-Spangled Banner' was never commissioned, and it was written by an amateur. What could be more American than that?"

What are some of the more surprising things we'll learn in this special?

On of the surprising facts is that "Rocket's Red Glare" refers to an actual device: Congreve Rockets, giant gunpowder-filled missiles designed to set fire to buildings. Our production team found an explosive expert who actually makes working replicas, and he fired off several for our cameras. It's pretty terrifying. We'll actually discover how much damage the British did to Washington: burning most of the public buildings, including the White House, the Capitol and the Library of Congress. Smithsonian curators actually show us a chunk of burned wood from the White House in 1814. We'll see how really hard it is to sing the National Anthem from Renee Fleming, the opera singer who performed "The Star-Spangled Banner" at the 2014 Super Bowl. It's difficult even for top opera singers.

What do you hope viewers take away?

What I hope viewers will take away is a fresh discovery of this song that we have grown really accustomed to. Americans have a strong emotional attachment to this song, but it turns out that only 40 percent of Americans actually know the words to "The Star-Spangled Banner!" I hope that by discovering the true story behind the Battle for America, and by seeing the reasons for Francis Scott Key’s emotional reaction to the flag, the viewers will be equally emotional the next time they find themselves singing "The Star-Spangled Banner." If you know that the destruction of America hung in the balance, then it really means something when you sing "the flag was still there."

This story was originally published in June 2014 and has been updated with new information.

'A Star-Spangled Story' about a flag, a song and a war
Smithsonian Channel special celebrates the surprising history behind the flag that inspired our national anthem more than 200 years ago.