Preparations are finalized for official opening of the National Museum of African American History and Culture in Washington.

WASHINGTON — Centuries of struggles and strife, decades of planning and pain, and years of hoping for a place that African-American history can call home will culminate as President Barack Obama officially opens the Smithsonian National Museum of African American History and Culture.

A shining bronze beacon on the National Mall, only steps away from a monument dedicated to a slaveholder president, the new Smithsonian will chronicle the complex relationship between the United States and a people it once enslaved, and tell the story of those who worked to make the necessary changes to bring the country to where it is today.

Thousands are expected to gather on the National Mall this weekend to watch the nation’s first black president cut the ribbon to open the museum. People are flying in from around the country to be some of the first inside, if they were lucky enough to get the coveted opening-day tickets.

Ground was broken for the new museum in 2012 on a five-acre tract near the Washington Monument after a decades-long push for an African-American museum on the National Mall. Congressman John Lewis of Georgia, a longtime civil rights icon, worked with then-Sen. Sam Brownback of Kansas to usher legislation through Congress, and President George W. Bush signed into law the bill that allowed the museum to move forward.

Construction was completed earlier this year on the 400,000-square-foot museum designed by British-Ghanaian architect David Adjaye. The museum strikes a unique shape on the Mall with its three-tiered bronze exterior panels inspired by an African wooden column.

Inside, museum officials say they have nearly 3,000 items occupying 85,000 square feet of exhibition space including exhibits like a Tuskegee Airmen training plane and the casket of Emmitt Till, a murdered African-American boy whose death helped rally the civil rights movement.

“It’s been 100 years in the making. So many people have dreamed about this, fought for this and wanted this to happen,” said U.S. Circuit Judge Robert L. Wilkins, who wrote the book “Long Road to Hard Truth” about the struggle to get the museum open. “It’s going to be a testament to their work and a testament to so many of our ancestors that this museum will open on the Mall.”

Millions of donors, both known and unknown, helped fund the museum. But some of the biggest donors’ names adorn the walls inside, including the Oprah Winfrey Theater; the Michael Jordan Hall: Game Changers; and the newest named addition, Robert F. Smith Explore Your Family History Center.