President Barack Obama marked the groundbreaking of the Smithsonian's National Museum of African-American History and Culture Wednesday, calling “not just an achievement for our time, but a monument for all time.

“This day has been a long time coming,” said Obama, the nation’s first African-American president, who noted that it was black veterans of the Civil War who had first issued a call for such recognition.

The museum -- which is being built near the Washington Monument -- is scheduled to open in 2015 and will be the only national museum devoted exclusively to the documentation of African American life, art, history and culture.

Obama called it “fitting” that the museum is being built on the National Mall – where he noted slaves were once traded -- and that it will sit near other “pillars of democracy,” including the White House and Capitol buildings, which he noted, were “built often by black hands.

“A time will come when few people remember drinking from a colored water fountain or boarding a segregated bus…” 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.”