Pronouncing this day a “long time coming,” President Obama on Wednesday hailed the groundbreaking of the National Museum of African American History and Culture that will open on the Mall in 2015.

View Photo Gallery: President Barack Obama and first lady Michelle Obama attend the groundbreaking ceremony for the Smithsonian National Museum of African American History and Culture on the National Mall in Washington, D.C.

Obama was among several dignitaries, including former first lady Laura Bush, who is a member of the museum’s council, to speak at the ceremony for the 374,000-square-foot museum, which has been more than a century in the making.

“The time will come when few remember drinking from a colored water fountain or boarding a segregated bus or hearing in person Dr. [Martin Luther] King’s voice boom down from Lincoln Memorial,” Obama said. “That’s why what we build here won’t just be an achievement for our time, it will be a monument for all time.”

The museum’s staff has raised about $100 million in private funds and collected about 20,000 artifacts for an exhibit that is expected to draw more than 3 million visitors a year. It will be the largest federally commissioned institution to focus on African Americans in the country.

Obama told the audience he thinks of his daughters, Malia and Sasha, and other young people someday viewing Harriet Tubman’s shawl or Nat Turner’s Bible and learning about how “ordinary Americans could do extraordinary things.”

“Men and women just like them had the courage and determination to right a wrong,” Obama added.

But he stressed that while the black slave experience would be part of the story documented by the museum, so too would the achievements of black cultural figures such as jazz legend Louis Armstrong.

“I want them to appreciate this museum not just as a record of tragedy, but as a celebration of life,” Obama said.

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