Baltimore celebrated the 200th birthday of “The Star Spangled Banner” on Saturday with music, tall ships and thousands of slightly damp but eager partygoers, some of whom donned their best red, white and blue attire for the occasion.

The Inner Harbor was awash in American flags. Tall ships from as far as Spain docked in the harbor, lending a dramatic and historic air to the festivities. But rain forced some to pull up their gangplanks to visitors for brief periods throughout the day. Street musicians played “Raindrops Keep Falling on My Head” in hopes of boosting the spirits of the soggy crowd.

David and Janet King of Beltsville, Md., were among those joining in the celebration, both decked out in red, white and blue ensembles.

“The ships are just amazing, and you don’t get much of a chance to see so many,” David King said.

Their plan was to tour the tall ships and other sights before grabbing a bite to eat and finding the perfect spot to watch the fireworks show.

Darlene McGinnis of Virginia Beach, right, helps to hold up a large American flag during the celebration of the 200th anniversary of "The Star-Spangled Banner" on Saturday in Baltimore. (Matt McClain/The Washington Post)

For an American history buff such as Jenny Semsell of Reading, Pa., the festivities were a nice break from a weekend of baseball games. Semsell and three of her friends had come to town for the Orioles and Yankees series but took a break Saturday. For Semsell, it was a chance to show off her knowledge of “The ­Star-Spangled Banner” and War of 1812 trivia.

The Navy’s Blue Angels performed despite the rain, though the show was briefly delayed.

“It looks like the bad weather is going to hold off here in #Baltimore & we’re looking forward to a great show! #rainraingoaway,” the team tweeted at one point.

More than a million people were expected to be part of a week-long Star-Spangled Spectacular celebration that also commemorates the battle between American and British forces for the city of Baltimore. The battle proved a turning point in the War of 1812. The celebration will continue Sunday with a speech by former secretary of state Colin L. Powell and a reenactment of the flag-raising that inspired Francis Scott Key to pen what would become the country’s national anthem.

Vice President Biden and Maryland Gov. Martin O’Malley were on hand for the evening program, which included a concert and fireworks at Fort McHenry, the site of the battle that spurred the poem. President Obama paid a private visit to the site Friday before attending a fundraiser in Baltimore.

More than 3,200 were expected at the concert, and organizers said they expected an additional 6 million to watch the broadcast live on PBS.

Beginning the morning of Sept. 13 and continuing for 25 hours, British forces fired as many as 1,800 bombs and 800 rockets in an attempt to destroy Fort McHenry and reach Baltimore.

As the story goes, Key, a 35-year-old Georgetown lawyer, was negotiating for the release of an American prisoner when he was detained by the British. Key watched the assault aboard an American truce ship while under Royal Marine guard, according to Steve Vogel, author of the book “Through the Perilous Fight: Six Weeks That Saved the Nation.”

The battle was so fierce, it wasn’t clear who had won, but when the mist and lingering smoke cleared, Key watched as the American flag was run up the fort’s flagpole.

Key’s originally titled his work the “Defence of Fort M’Henry,” but music publishers later changed its name to “The Star-Spangled Banner.” (Interesting side note: Key was tone-deaf.)

The song officially became the national anthem in 1931.

The 200th anniversary of that fateful battle was a chance for parents to indulge a few teachable moments Saturday, though in some cases, the adults appeared to be having more fun than their children.

Carl and Jenny Fischer of Pasadena, Md., brought their three children — twin sons Xander and Logan, 11, and daughter Jane, 3 — to the festivities.

“This is a once-in-a-lifetime event,” said Carl, who gamely donned a black paper copy of a black shako hat given out as part of the celebration. The shako is a tall, cylindrical hat with a visor that British soldiers would have worn during the War of 1812. American soldiers would have donned similar head wear, made of heavy felt.

And even though the Fischer boys were not so interested in the hat, Carl Fischer wore it like a — yes — good soldier.

Near where the tall ships were docked, Jimmy Batty, 13, said he had heard the story of “The Star-Spangled Banner” in his social-studies class and was excited to have the chance to visit the site where the battle took place.

His stepmother, LeAnn Batty, agreed.

“It’s nice to be able to bring him here, because it really makes history come alive,” she said, remembering a similar trip to Baltimore to see tall ships during the bicentennial celebrations in 1976. “It’s nice to be able to do this together.”