At the heart of the nation's first museum devoted to the history of Arab-Americans is a mosaic-decorated courtyard surrounding a small fountain, evoking the traditional courtyard of Arab lands. A symbol of hospitality, it is also, typically, a feature of one's home, and this museum is, in its way, a declaration that Arab-Americans really are at home, not just in Dearborn (where some 30 percent of the 100,000 residents identify themselves as Arab-Americans) but in the United States itself.

The surest sign of that may be that, like other groups, they have built this museum honoring their past and their identity. And the 38,500-square-foot, $16 million Arab American National Museum, which opened in May, is, like other museums of American hyphenation, at once an assertion of difference and of belonging, a declaration of distinction and of loyalty. It would be making a political statement even if it weren't directly across the street from City Hall.

The museum was also designed to reflect the interests of its constituency: Arab-Americans. That is a source of its strengths, and suggestive too of its weaknesses: it eagerly wants to celebrate that identity and create a strong political front; it is less interested in reflecting on difficulties and making distinctions. Before the museum was begun, a group of planners, including a sociologist, Anan Ameri, who became its director, spent six months traveling to Arab-American communities, soliciting ideas.

"The museum was built to tell our story," Dr. Ameri explained before leading a critic on a tour. "But before we can tell our story, we have to know what the Arab-American story is."

"People don't know" was a recurring refrain in these consultations, Dr. Ameri said. "People don't know" about who we are, went the complaint. So the museum includes a handsome library and an exhibit chronicling the arrival of Arabs on American shores, including such unusual figures as Hadj Ali, a 19th-century Syrian immigrant recruited by the United States to train camels for the Western deserts.

"People don't know" about Arab contributions to civilization, continued the refrain, so surrounding the central courtyard are display cases summarizing achievements of early Arab civilization; or about everyday life, so another exhibit shows how typically American Arab-Americans have become; or about their accomplishments, so another display shows Arab-Americans in politics (John Sununu), political activism (Ralph Nader), literature (Kahlil Gibran), journalism (Helen Thomas), movies (William Peter Blatty) and opera (Rosalind Elias).