The African American History Museum won't open for another year, but a high-tech projection turned it into a movie screen for a few days. (Lavanya Ramanathan/The Washington Post)

The National Museum of African American History and Culture shone a light Monday on a major milestone — the completion of exterior construction — by lighting up the museum itself.

At a gathering that director Lonnie Bunch called the museum’s “very first event,” he promised an opening in a year’s time and unveiled a large-scale projection that will be visible to passersby for the next two nights.

“There are few things as noble as remembering all our ancestors,” Bunch told the crowd, which featured a number of high-profile names, including one of the museum’s architects, David Adjaye, and longtime civil rights advocate Rep. John Lewis (D-Ga.).

The night’s showpiece was a 7 1/2 -minute film that rendered those ancestors larger than life. It cast more than a hundred years of African American progress across the five-story building, illuminating the museum with the faces of Marian Anderson, Frederick Douglass, black soldiers and dozens of others recognized in history books and not.

The high-tech projection, “Commemorate and Celebrate Freedom,” flitted from the ratification of the 13th Amendment, which ended slavery in 1865, to the passage of the Voting Rights Act of 1965, dancing across the west and south walls of the new museum.

People cross 14th Street as images marking the ratification of the 13th Amendment, passage of the Voting Rights Act and the end of the Civil War are projected during the "Commemorate and Celebrate Freedom" event at the National Museum of African American History and Culture on November 16, 2015 in Washington, D.C. (Ricky Carioti/The Washington Post)

The display will continue through Wednesday, turning on each evening at 5:30 and going dark at 9 p.m.

The project, Bunch said before the event, will serve as the opening salvo of a “formal drumbeat” to opening day, expected to take place in late 2016.

On Monday night, it was in fact the sound of drums — of the Soulful Symphony drum ensemble — that kicked off the festivities. District Mayor Muriel E. Bowser spoke of the city’s place in the annals of African American history, of its contributions to the arts and culture with the theaters that made up U Street’s Black Broadway, and Howard University’s role in higher education. D.C. Del. Eleanor Holmes Norton (D) recalled the District as a model for emancipation. A group read the verses from Margaret Walker’s “For My People,” and finally, gospel singer BeBe Winans and the Soulful Symphony lifted the bundled-up crowd on a nearby slope with a pair of rousing numbers, including “America America.”

Later, as the imagery lit up the museum’s surface, some in the crowd said that they’d come not only to watch the show, but also because they wanted to support the museum.

Ayana Douglas of Columbia Heights had made the outing with her family. The kids didn’t understand everything they’d seen, but 6-year-old Sienna recognized Frederick Douglass, and that was enough.

“I can’t wait for [the museum] to open,” said Shawn Hart of Southwest Washington, who had set up on the slope with blankets and folding chairs.

Projected onto the unusual canvas of a $540 million, ­five-story building at 14th Street and Constitution Avenue NW, “Commemorate and Celebrate Freedom” offered a glimpse of what visitors may see when the museum opens next year: Many of the historic photos in the film came from the museum’s growing trove.

The cost of the project, including Monday’s opening-night performance, was $1.7 million.

Stanley Nelson, the renowned “Freedom Riders” documentarian and 2013 National Humanities Medal recipient, and his wife, Marcia Smith, were tapped to create the film. Before Monday’s lighting, the couple, who are also consulting on permanent exhibits at the museum, described the 3-D projections as a new challenge.

“It’s a film, and it’s not a film,” said Nelson by phone from New York. “So much is involved in the technology to make this thing work.”

Added Smith: “There’s no narration, there are no interviews, and those are elements that we are accustomed to working with.”

The technical work of getting the images onto the building was taken on by Quixotic, a multimedia company in Kansas City, Mo. Using architectural renderings of the building, the firm created a 3-D virtual map, then designed the projections to fit precisely.

Washingtonians last witnessed a major site-specific projection in 2012, when California artist Doug Aitken projected his 360-degree piece, “Song 1,” onto the Hirshhorn Museum’s convex surface nightly for nearly two months.

This week’s projections had to work on both the building’s unusual stair-step “corona” silhouette and its dark bronze exterior, which has a filigree texture.

To compensate for those factors, 24 projectors, each 10 times brighter than what you’d use to show a PowerPoint presentation, have been installed on the Mall. (On Monday night, the film was still hard to see.)

Smith, the filmmaker, said that she hoped “people look at this piece and think about their own place in this history.”