Washington ? 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 vs. 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 Washington 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 last week, and the American History exhibit, which opened Saturday, 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 vs. Board at Fifty” at the library is open until November. “Separate Is Not Equal: Brown vs. Board of Education,” at American History, will close in 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; 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.