When President Obama helps dedicate the National Museum of African American History and Culture on Saturday in Washington, he'll be marking the debut on the National Mall of the black experience.

Starting from nothing, over the last decade and a half, the museum has acquired a collection of close to 40,000 objects and documents; more than 3,000 will be on exhibition when doors open at 1 p.m., after a musical prelude and a dedication ceremony that begins at 9 a.m.

By virtue of its size and national focus, the museum will obviously be telling a sweeping story. But that story has innumerable strands, and one thing should be clear to anyone visiting: Philadelphia is a key center for African American history, culture, and collecting, often in unexpected ways.

A church pew from Richard Allen's original Bethel Church at Sixth and Lombard Streets; intimate items belonging to Harriet Tubman; Thom Bell's piano, used in fashioning the Philadelphia sound with Kenny Gamble and Leon Huff; memorabilia celebrating movies and stars of the race-film industry that flourished on Vine Street in the 1920s - all show the city's outsize role in the making of not just black America, but all America.

There are fashionable hats attesting to the city's vivid role in the world of human display; an exhibit highlighting the story of George Washington's enslaved chef Hercules; a broadside written by Frederick Douglass exhorting "Men of Color" to join the Union forces in 1863.

Philadelphia as portrayed in the museum is a place where things are made, styles are set, actions are taken, and all is documented.

"We a BaddDDD People," Sonia Sanchez's 1970 poetry chapbook announces at the museum. Sanchez was named Philadelphia's first poet laureate in 2012.

"Before there was an African American museum [in Washington], how did African American stories get into places?" asks Richard S. Newman, a professor of history at the Rochester Institute of Technology and former head of the Library Company of Philadelphia.

One way, he said, was through the collecting efforts of places like the Library Company, the Historical Society of Pennsylvania, and Mother Bethel Church.

"That's one of the ways people became attuned to the power of black artifacts," he said. "This is a great town for collecting stories . . . that have been suppressed so long."

Charles L. Blockson, curator emeritus of the Blockson Afro American Collection at Temple University, has been collecting suppressed stories for more than six decades. He donated 39 items belonging to abolitionist Harriet Tubman to the national museum.

Harriet Tubman's shawl and hymnal, donated by Charles Blockson, curator emeritus of the Blockson Afro American Collection at Temple, are on display.

The donation included Tubman's handmade knife and fork, the silk shawl given to her by Queen Victoria in 1897, and Tubman's personal hymnal.

Bliss and Shankey's Gospel Hymns No. 2 falls open to "Swing Low, Sweet Chariot," Tubman's favorite, sung at her funeral in 1913.

"People all over the world know about Harriet Tubman," Blockson said. Not only that, but Tubman helped guide Blockson's own ancestors along the Underground Railroad to freedom.

Gwen Ragsdale, cocurator of the Lest We Forget Slavery Museum in Port Richmond, and her husband, Joe, have accumulated iron shackles, leg- and handcuffs, collars, head gear, branding irons, and similar materials for more than half a century.

"All of this shows how different coming to America was for African Americans," she said. The Ragsdales have talked extensively with the national museum but have not yet sent anything to Washington.

Efforts by institutions like the historical society and collectors like Blockson and the Ragsdales have been critical in preserving memory and identity, Newman said: "They're the building blocks" for the national museum.

Sometimes those building blocks are just going about their daily business when they bump up against history.

That's the case with Kenny Gamble, Leon Huff, and Thom Bell. Gamble and Huff built Philadelphia International Records, which put an indelible stamp on American popular music beginning in the 1960s. Pianist and composer Bell joined them in their songwriting and publishing efforts.

Their work belongs in the museum because "Gamble, Huff, and Bell are American success stories and created a sound track for our lives," said Dyana Williams, a producer, broadcaster, and Gamble's former wife.

"They didn't go to Harvard Business School, they didn't go to Wharton, but they built a multimillion-dollar business with a global sound track," she said.

Maybe Mae Reeves, now 103, can top that, so to speak. For half a century, she ran her own millinery business - Mae's Millinery Shop, on South Street and then on North 60th Street, creating the swankest of chapeaux for such luminaries as Ella Fitzgerald, Lena Horne, Marian Anderson, and Leonore Annenberg.

The national museum will exhibit about 30 of her hats featuring feathers, satin, velvet, ribbons, flowers, sequins, glitter - you name it.

A white lace hat with floral design in the exhibit honoring Mae Reeves and her West Philadelphia hat shop. Ed Hille / Staff Photographer

"Yeah! I made stuff that they wanted!" Reeves said of her customers at a ceremony announcing the Smithsonian acquisition.

In making hats and building a business, she also inspired younger people with the possibility of making successful lives on their own. And this is clearly an important part of the national museum's storyline.

Yes, the African American experience has been hard and often brutal. But there are green shoots that push out of the hard, unforgiving earth.

Richard Allen, humiliated by white churchgoers, strikes out on his own and builds a church, now known as Mother Bethel, and a whole denomination, the African Methodist Episcopal Church.

Tubman escapes from slavery, turns around, and helps hundreds of others flee to start new lives, inspiring millions during her lifetime, including Queen Victoria.

Gamble, Huff, and Bell turn hardscrabble lives into a recording empire, and Gamble takes his gains and plows them back into his old South Philadelphia neighborhood.

Blacks are blocked from making films in white Hollywood, so they create their own filmmaking worlds in Chicago and Philadelphia.

Beverly Richards, steward of the collection of race-film memorabilia collected by her late husband, Larry Richards, notes that segregation and exclusion created an entire industry.

Blacks owned their own theaters here, she said, like the Standard, the Idle Hour, the Dunbar, and the Royal. They made their own films and created their own stars.

"Philadelphia was one of the most important players in that whole industry," Richards said.

The Smithsonian now has 1,000 pieces from the Richards collection, including movie posters, Sammy Davis Jr.'s childhood tap shoes, an evening gown owned by Dorothy Dandridge, and first editions of books by black director and writer Oscar Micheaux.

Says Lonnie Bunch, the national museum's founding director: "I think the museum needs to be a place that finds the right tension between moments of pain and stories of resiliency and uplift."

The African American Museum in Philadelphia, at Seventh and Arch Streets, a Smithsonian affiliate, will host a video "watch party" of opening-day celebrations for the mothership on the mall, said Patricia Aden, AAMP president and CEO.

215-854-5594

@SPSalisbury