"Would America be America without her Negro people?"

That's the question W.E.B. Du Bois asked in 1903.

A little more than 100 years later, radio and television talk-show host Tavis Smiley attempts to answer it with "Tavis Smiley Presents America I Am: The African American Imprint" exhibition, a free sneak-preview tour of which will be in Pittsburgh tomorrow.

"What the exhibition does is tells the story of the African-American imprint on this country for the 400 years that we've been here, starting with the first slaves who arrived in Jamestown, Va., 400 years ago all the way up to Barack Obama," Smiley said.

"It's important to know that there is a back story to Barack Obama. He didn't just fall out of the sky. There's a back story that made this moment possible."

Sponsored locally by the August Wilson Center for African American Culture, the tour's 18-wheel super truck will be in Parking Lot 6 at PNC Park from 10 a.m. to 4 p.m.

There's been "so much black history and so much American history that's come out of the great City of Pittsburgh," Smiley said, that it had to be one of the more than 30 cities included in the mobile preview.

After visiting the minimuseum on wheels, people can go into the truck's studio to videotape what they think the African-American imprint has been on America and how they plan to make an imprint.

These will be collected to amass what Smiley believes will be the largest oral history project in the country.

The super truck will give visitors a glimpse of the full 12-gallery, 15,000-square-foot exhibition, set to open in November. Sponsored by Wal-Mart and developed by Arts Exhibition International -- the company that did the recent King Tut exhibit -- "America I Am" will spend four to six months in major museums across the United States over the next four years.

While Smiley would not reveal which city will be first to get "America I Am," he did drop some hints.

On Thursday, he'll make the announcement alongside that city's mayor. Here's the clue: Smiley will be in Philadelphia this weekend, as will the touring exhibit.

He said there are many wonderful museums across the country dedicated to telling the story of African Americans, but what makes his exhibition unique is the scale and the variety of artifacts, including items from Du Bois, the Rev. Dr. Martin Luther King Jr., Booker T. Washington and Muhammad Ali.

"Never before has this much black history been assembled in one place," Smiley said. "It gives the chance for all of America to see what the contributions of African Americans have been to this country."