WASHINGTON — Rep. Frederica Wilson had a chance recently to take a private VIP tour of the Martin Luther King Jr. National Memorial, but she turned it down. Too soon, she said.

“I want to get thrilled seeing it unveiled, to feel the passion,” said Wilson, D-Fla. “I want to see the glory of the statue in a finished state. I want to be wowed with everyone else seeing the finished product.”

Wilson will be among an anticipated crowd of more than 250,000 spectators Sunday for the dedication of the King memorial — a tranquil monument of stone, greenery and trees along the northwest edge of Washington’s Tidal Basin that will honor the slain civil rights leader.

Sunday’s ceremony, which coincides with the 48th anniversary of King’s “I Have a Dream” speech, will officially open the first monument on the National Mall honoring an African-American.

The $120 million memorial is part of a burgeoning number of monuments in the nation’s capital recognizing African-American contributions to American life and culture.

On Washington’s busy U Street corridor, the African American Civil War Museum recently reopened in a new, 5,000-square-foot home to better tell the story of the 200,000 slaves and freed African-Americans who fought in the conflict.

At the U.S. Capitol Visitor Center, tourists can view two plaques placed by Congress last year to recognize the little-known fact that government-rented slave laborers helped construct the U.S. Capitol building.

Back on the National Mall, plans are under way for the National Museum of African American History and Culture, which will be part of the Smithsonian Institution’s 19-museum complex when it opens in 2015.

Ground won’t be broken on the $500 million building — to be located near the Washington Monument — until next year, but curators have been busy amassing more than 10,000 artifacts since 2005, and expect to acquire 10,000 more by the museum’s opening day.

The prized acquisitions include a silk and linen shawl given to Harriet Tubman by Queen Victoria, a biplane used by the Tuskegee Airmen, items from the popular African-American TV dance show “Soul Train,” and the original coffin of Emmet Till, the 14-year-old African-American boy who was brutally murdered in Mississippi in 1955 after he allegedly whistled at a white woman. His open-casket funeral was a focal point in the civil rights struggle.

“What’s happening here is, finally, the world of museums and monuments are recognizing what we have known in the last 50 years, and that is the history and import of African-American culture is one of the most important things in our history,” said Lonnie Bunch, the founding director of the Smithsonian’s African-American museum. “The African-American experience is a constant in defining America. The African-American story is everybody’s story.”