Entertainer Bill Cosby has agreed to donate the proceeds from 10 of his shows to the planned National Slavery Museum in Fredericksburg.

Ed Wegel, co-chairman of the museum's capital campaign, said the donation is scheduled to be announced tomorrow night at a private showing of artifacts that will become part of the museum's collection. It represents the first fundraising coup for the project, which will cost an estimated $200 million.

Cosby, a member of the museum's board, could not be reached yesterday for comment. The performances have not been chosen, according to Wegel, who said fundraising dinners and receptions will be held in conjunction with the shows in an effort to rally nationwide financial support for the museum.

Including ticket sales -- seats are $40 to $75 each, depending on the city -- and the parties, officials said the gift could amount to as much as $20 million.

The museum has generated academic interest and geographic disagreement. Some supporters have said it should be built in Washington or Jamestown, Va., where African slaves first landed in 1619, rather than in a commercial development in Fredericksburg. The museum site is part of Celebrate Virginia, a retail and office complex that includes a golf course.

Cosby, known for his stand-up comedy and his sitcom role as Dr. Cliff Huxtable, has created controversy recently by criticizing some black parents for not properly raising their children and some black children for using poor language and bad manners.

The announcement of his gift, expected at a gala at the University of Mary Washington, will be part of a recent series of activities aimed at publicizing plans for the museum. Its founder and chairman, former Virginia governor L. Douglas Wilder, has said the museum will explain slavery as a global, economic story, rather than strictly as a tale of American racism. Historians still debate whether the dominant force behind slavery was economics or race.

The museum put some of its newly acquired artifacts on display for the first time this summer in an exhibit at the college. The show, which runs through Oct. 8, includes African art, slave shackles, magazine articles and cartoons showing the evolution of attitudes toward blacks and slavery. Prominently displayed are pencil portraits by Wilder's daughter Lynn.

The exhibit has drawn nearly 1,000 visitors, an unusually large number for the college's Ridderhof Martin Gallery, director Thomas Somma said. The museum is expected to open in 2007.