If there's an ethnicity not in need of a museum to bear witness to its exquisitely realized ambition, it's that of the American Jew. In science, Jews lay claim to Einstein; in music, Bernstein. It's hard to think of a group that in the last century has more clearly led media and entertainment, finance and commerce.

American Jews might be the most spectacular overachievers in our young country's history, and it's never been much of a secret.

The assumption for many who tracked development of the new home of the National Museum of American Jewish History was that it would be a vanity project. The unfortunate timing - fund-raising took place in a severe recession, as Bernard Madoff's Ponzi scheme sent spasms through Jewish philanthropy - only gilded the sense of folly.

But in its opening state, at least, the new $150 million Jewish Museum on Independence Mall turns out not only to do justice to its subject, but in some cases makes the material soar. Its three themed floors, plus a ground-level hall of fame, are layered with the kind of substance from which three- and four-hour visits can be wrought. It's a serious place of learning and, in quiet, airy coves overlooking Independence Hall and its environs, contemplation.

There are caveats galore. Can marketers tune their message finely enough to attract the national and non-Jewish visitor they covet? Will the museum be able to fund itself sufficiently to replenish exhibitions often enough to draw repeat visitors? Many of the museum's artifacts are on loan - 40 percent to 45 percent, according to Josh Perelman, deputy director for exhibitions, programs and collections - suggesting both terrific opportunity and intensive ongoing work critical to freshening the experience.

Curatorial evolution is inevitable. But at the moment, the museum is, for Jews already highly schooled in their cultural and theological identity, more of a brush with pride than revelation. For the moderately self-aware Jew, the museum rekindles a cultural history you heard your grandparents talk about over dinner, now perhaps lost in the dim haze of childhood.

What is often missing from common lore, with so many Jews of families who came to this country in the last century or so, is the common commingling of Jews with other earliest Americans. Organized chronologically, the museum's story begins on the fourth floor (you'll want to start there and work your way down) with two ships landing in New York in 1654: the Sint Catrina, delivering 23 Jewish men, women and children, from Recife, Brazil; and the Peereboom, which carried Dutch merchant Jacob Barsimon. They are the Jewish Nina, Pinta and Santa Maria, bringing to North America its first permanent Jewish settlers.

Several galleries are devoted to early American Jewish life - in expected places like Baltimore and San Francisco, but also in the mining town of Trinidad, Colo., where a B'nai B'rith chapter was founded in 1878. It's a small thrill to come nearly nose to nose with a lustrous tan deerskin hide fashioned into a Torah, a gift from London to the Jews of Savannah, Ga., in 1737.

It doesn't take long, of course, for American Jews to come up against bigotry. Gov. Peter Stuyvesant considered them "hateful enemies and blasphemers of the name of Christ" (he didn't think any more highly of Lutherans or Quakers). In New Amsterdam, overseen by the Dutch West Indies Co., Jews could not own property, worship in public, hold office, or open a shop.

This theme - Jews restricted, persecuted, even lynched - continues through exhibits exploring eras as late as the 1960s, and elides with the civil rights movement. Obstacles, though, come in measured doses, bitter counterpoint to larger forces of ambition, assimilation, and the struggle to keep one's cultural identify in the New World.

If the early-American experience is meaty and didactic, the 20th century carries emotional punch.

It's one thing to have a textbook knowledge of the Ku Klux Klan, and another to stand before an actual white hood from 1930 that unspools the story of the lynching of Leo Max Frank. The hood comes from a Klan group that included members of the Knights of Mary Phagan, the mob that in 1915 lynched Frank, a Jewish factory superintendent accused of murdering Phagan, 13. The case led to the founding of the Anti-Defamation League.

To sit before a screen and hear a now-elderly American soldier recall the liberation of Dachau in a short aural/visual history is to once again be confronted with the impossible depths of inhumanity. As he describes three buildings and their contents, you see corresponding images - one room with locks of hair, some still braided, heaped high for some unspeakable future use; another with disembodied teeth being harvested for gold, a third piled with empty suitcases still labeled with the names of owners who will never use them again.

Previous knowledge of the Holocaust does nothing to numb this kick in the stomach. You're struck by the passing of a generation of eyewitnesses, and the urgency of sharing their stories with a sometimes willfully forgetful world. (Of course, it's often those who need this museum most who will never see it.)

Rosy nostalgists will find their own meaningful icons of the past. There's a section on New York's Henry Street Settlement, originally founded to give medical care to Russian Jewish women (though its mission later expanded). Samovars and seltzer bottles will strum emotional chords for many. There's something inexplicably meaningful about coming upon an item you saw every day in your house now displayed in a museum vitrine (in my case, The Jewish CookBook by Florence Kreisler Greenbaum).

Newer museum technologies are used to good advantage. In one nook, viewers can watch documentaries running in loop that tell personal stories of the pogroms and economic conditions that led Jews to flee their homelands, the footage thrown onto nearly three dozen curled screens shaped like blowing pages.

It's not always clear which way to move within the 25,000 square feet of exhibitions, designed by Gallagher & Associates to cover "Foundations of Freedom" (1654-1880), "Dreams of Freedom" (1880-1945), and "Choices and Challenges of Freedom" (1945-present). But it doesn't much matter. History lessons are tucked away at every turn.

What happened in Saratoga Springs, N.Y., in 1877? What was the Johnson-Reed Act of 1924, and what did it mean to Jews? Why didn't the Allies respond more forcefully and quickly after word of Hitler's Final Solution leaked out? Who was Father Coughlin? Führer Kuhn? You can't understand the 20th century, or be fully equipped to face the 21st, without knowing.

The museum's content will evolve, and perhaps, too, its presentation. Labels are often short on context and explanation. A "Real Men Marry Rabbis" T-shirt is funny - but what does it mean? Does it refer to men marrying female rabbis, or male? A Civil War-era chromolithograph shows an oft-repeated image from the era, a soldier asleep near a battlefield, dreaming of reunion with his family. But is this the progenitor image in the genre - or simply a copy by an engraver who happens to be Jewish?

Lots of small problems add up to some frustration. Some visitors will be thwarted by gray-on-gray type in dimly lit rooms. In one gallery, it shouldn't be so hard to figure out that the painter of a portrait is Thomas Sully. It was a smart idea to highlight, simultaneously on two screens, key moments for Hitler and Franklin D. Roosevelt in the run-up to World War II. But the screens are so far above eye level that to spend any time with them means a crick in the neck.

Once in a while you feel that the museum falls into the trap of simply rattling off names of people you may not have known are Jewish. Touch screens on the first floor allow you to sort a list of famous Jews.

Louis I. Kahn? Jew.

Henry Kissinger? Jew.

Sidney Kimmel. Who?

Oh, right -the museum's largest donor, at $25 million.

Much more intriguing is the idea, revealed in an exhibition area about Jews in the movies, that Betty Boop sprang from the imagination of Jewish animators. Betty Boop a Jew. Who knew?

Contact culture writer Peter Dobrin at pdobrin@phillynews.com or 215-854-5611. Read his blog at www.philly.com/philly/blogs/artswatch/.