The museum's concept seems clear enough to Lewis, who as a young man endured beatings and even suffered a concussion while marching for voting rights for blacks. It needs to personify the African-American experience. But the location is a different matter. The museum's authorizing legislation includes four sites for consideration. One is the Arts and Industries Building, which is currently closed for renovations. A second is a parcel of empty park space directly northeast of the Washington Monument. A third is the current site of the Liberty Loan Building on 14th Street Southwest. And the fourth is an eight-acre perch overlooking the Southwest waterfront at the end of the L'Enfant Promenade. The Smithsonian Board of Regents is expected to select a site from this list by early next year, after it receives the results of a year-long site-evaluation study by two engineering firms, and after it consults with a variety of entities, including the National Capital Planning Commission and five Congressional committees. Lewis - who has worked for years to see the museum realized and whose House Web site home page prominently features a link to the museum - will also be consulted.