Re-creating the school segregation of the early 20th century is an emotional minefield many curators would dance around. Most would let the black-and-white photographs of the time show the disparities: tarpaper shacks and an outhouse for black students; brick buildings with indoor plumbing for white pupils.

But to demonstrate fully how monumental the famous school desegregation case Brown v. Board of Education was in 1954, the basic nonsense and degradation of segregation has to be understood. The curators at the National Museum of American History decided to offer museum-goers the experience of physically entering a mock classroom, separated into colored and white sections, with a shared bench for the black students and individual desks for the white pupils.

"You can't understand the significance of Brown unless you understand legalized segregation. People understand slavery, prejudice, but if they don't have a personal experience with segregation, it's a tougher concept," says Harry R. Rubenstein, a curator of the Brown exhibition. On a wall is a list of Jim Crow laws, such as blacks and whites could not play checkers together in Birmingham, Ala., and blacks and whites had to have separate phone booths in Oklahoma. "Darkies Bathing Prohibited" warns one sign.

The lesson hits home.

American History is one of two local institutions -- the other is the Library of Congress -- that have combed their considerable archives and gathered other memorabilia to tell the story of Brown on its 50th anniversary. Both the library show, which opened this week, and the American History exhibit, which opens tomorrow, use almost the same number of primary objects -- about 110 in each show. And they have similar narrative frameworks, from the early legal battles in the 1800s to the promised freedoms of emancipation, to the legal cases that led to Brown, to the two towering legal personalities of the case, Charles Hamilton Houston and Thurgood Marshall, to the aftermath and school issues today.

" 'With an Even Hand': Brown v. Board at Fifty" at the library is open until November. "Separate Is Not Equal: Brown v. Board of Education," at American History, will close next May.

The two exhibitions successfully frame the place, time and importance of Brown. Both are handsome and replete with so much reading that the fundamental impact of the case will have plenty of time to penetrate. The museum show stands apart because of the immersion of the mock classroom and also because it takes a closer look at the five communities -- Topeka, Kan.; Farmville, Va.; Wilmington, Del.; Washington, D.C.; and Clarendon County, S.C. -- that sparked the local cases that were bundled into the Brown decision.

These are shows about legal work, and many of the emotions, both black and white, are buried in the words. By sunset of May 17, 1954 -- the day the Supreme Court delivered its decision -- it was clear that segregationists had another rallying cry. And though most blacks knew Brown was just a beginning, they took a moment to relish the fact that a Supreme Court decision, crafted by brilliant black legal minds, was a new tool in the long fight.

Both shows illustrate the value of the defining object.

On an old onionskin, a Supreme Court clerk typed a draft of the follow-up orders to implement the decision, which were released by the court in 1955. Justice Felix Frankfurter crossed out "issued forthwith" on the draft and substituted the expression he borrowed from Oliver Wendell Holmes. In pencil, Frankfurter wrote "with all deliberate speed," the phrase that became a lightning rod. The paper is framed at the library.

The museum includes a Ku Klux Klan robe at the beginning of the exhibition and, at the end, the robe of Marshall, who served on the Supreme Court from 1967 to 1991. There is a textbook, stamped "white schools," that was handed down to black students in Raleigh, N.C. The exhibition also has the dining room table from Lucinda Todd's home in Topeka, which the members of the NAACP and the family of Linda Brown and the other local plaintiffs sat around to map out strategy.

To show how Brown was built upon decades of legal cases and human determination, the two shows start in the early history of the United States. The library has retrieved from its rare manuscripts collection a personal narrative written in 1854 by Margaret Douglass, a white woman who was jailed for teaching free black women to read. The museum has included the pen that President Ulysses S. Grant used to sign the 15th Amendment, which gave all adult men the right to vote. The museum also borrowed from the Supreme Court the docket used to record each vote in Plessy v. Ferguson, the case that legalized segregation in 1896. The library, by contrast, has simply opened a law book to the case brief.

The show at American History has the advantage of a larger space, which it uses judiciously in explaining the context of segregation, the central role of the drive for quality education at all levels of black life, a breakdown of the case through a well-organized timeline and the aftermath of Brown.

Though smaller, the library exhibition does not feel inadequate, thanks to the strength of its documents. The library drew heavily from the archives of 22 Supreme Court justices and the millions of items in the archives of the National Association for the Advancement of Colored People.

"Having that collection gives us the unique opportunity to trace the case throughout the battle for legal rights and the fight for equal education," said Adrienne Cannon, one of the show's curators. The early papers of the NAACP show "a free and complete education" was always part of its mission.

The museum unearthed a handbill to recruit blacks to fight in the Civil War, and part of the background is a school building to show how education was a part of freedom. The library used another rare book with the 1849 argument made by Charles Sumner in a Massachusetts courtroom that the Boston schools were unlawfully segregated.

Both exhibits lavishly use the wordless power of photography. The library has included pictures of school buildings that were believed to be taken by attorney Houston on his tours of the South and similarly evocative ones by the noted photographer Marion Post Wolcott. It also has a photo taken by Gordon Parks of psychiatrist Kenneth Clark performing his famous test on black youngsters about whether they preferred a black doll or a white doll. The library also dug into its music collection and displays the score for "Fables of Faubus," a composition jazz great Charles Mingus wrote about the segregationist governor of Arkansas.

Notes of congratulations on the Brown decision sent to Chief Justice Earl Warren from other justices and public figures are included in the library history. "They all know what a major step this was," said Daun van Ee, one of the exhibition curators and the library's 20th-century American history specialist.

For years Brown reverberated as the fight for integration was waged through mass marches, acts of courage, deaths and more legal maneuverings. Both shows condense this history. One document at the library encapsulates this struggle: the arrest record of Rosa Parks on Dec. 5, 1954. It was another watershed moment and prime evidence that all deliberate speed would take years and the work is unfinished.

Dorothy Geraldine Counts, 15, is taunted as she walks to enroll at Harding High in Charlotte, N.C., in 1957.At left, George E.C. Hayes, left, Thurgood Marshall and James Nabrit celebrate the Supreme Court declaration that segregated public schools are unconstitutional. The decision sounded the end of one-teacher schools for black children, such as the one above in Greene County, Ga., in 1941.