Topeka ? With several hundred people watching outside a building that once was part of a segregated school system, the U.S. Postal Service unveiled new stamps commemorating the civil rights movement.

The 10 stamps recall events from President Truman’s 1948 order integrating the armed forces to congressional approval of legislation protecting blacks’ voting rights in 1965.

Also honored is the 1954 U.S. Supreme Court decision declaring school segregation unconstitutional, and for that reason, the Postal Service had one of six ceremonies in a tent outside the national historic site dedicated to Brown v. Board of Education. The building once was Monroe School, one of four all-black elementary schools in the city.

About 100 fifth-graders from the nearby Williams Fine Arts and Sciences Magnet School – built a decade ago to satisfy continuing litigation over Topeka’s schools – formed a choir and wore multicolored T-shirts. One song, borrowed from “School House Rock” of children’s television, was the preamble of the U.S. Constitution set to music.

The new stamps pleased Zelma Henderson, who as the mother of two young children joined 12 other parents, including the Rev. Oliver L. Brown, as plaintiffs in a 1951 lawsuit challenging Topeka’s segregated schools.

“I think we all need reminders of what some of our people went through,” said Henderson, now 85, the last living parents who filed that lawsuit.

The postal service also had events in Montgomery and Selma, Ala.; Little Rock, Ark.; Greensboro, N.C., and Washington. Events planned in Memphis and Jackson, Miss., were canceled because of Hurricane Katrina.

The set is “To Form a More Perfect Union.”

United States Postal Service employee Larry Dreher, left, puts a cancellation stamp on a new Brown v. Board of Education stamp for Amy Bixler Kelly, of Lawrence. The new stamps commemorating the nation's civil rights movement were unveiled Tuesday at the Brown v. Board of Education National Historic Site in Topeka.

It also honors a 1955 boycott of buses in Montgomery protesting the treatment of black riders; the integration of Central High School in Little Rock in 1957; a sit-in at a segregated lunch counter in Greensboro in 1960; freedom riders who attempted to integrate public transportation in 1961; the 1963 civil rights march on Washington; the approval of 1964’s federal Civil Rights Act; and the 1965 civil rights marches in Selma.

Postal officials typically release between 20 and 25 sets of commemorative stamps a year, but events in multiple cities are rare, said Roy Betts, who manages campaigns promoting such products for the Postal Service. He said 50 million sets of the civil rights stamps will be printed.

Cheryl Brown Henderson, a daughter of Oliver Brown and the president of an educational foundation bearing the family’s name, said the stamps are a creative way to remind Americans of their history.

“People will be learning, without knowing they’re really learning,” she said.