One of Elizabeth "Betita" Martinez's earliest memories is of boarding a bus with her father in her hometown of Washington, D.C., and being told by the driver to sit in the back of the bus.

For Martinez, who is of Oaxacan ancestry, that experience left an indelible memory. Although only 6 years old, she remembers, "I knew something was wrong."

As a result of her early awareness of racial inequality she forged a close bond, later in life, with the African American civil rights movement. Later as a writer and teacher and the author of "500 Years of Chicano History," she became an important voice in the Chicano movement and an important link between both struggles.

In the 1950s, while working as a researcher for the United Nations, she was inspired by the great social movements for justice around the world.

Then in 1963, when four little girls were killed by a Klan bomb in Birmingham, Alabama, Martinez felt another deep emotional surge. "I was enraged." From 1960 until that moment, she had been collaborating with the Student Nonviolent Coordinating Committee (SNCC), one of the principal groups involved in sit-ins at lunch counters and voter education in efforts to desegregate the South. Now she joined the organization as a full-time staff member.

In the Freedom Summer of 1964, shortly after the bodies of three murdered civil rights workers were found in a dam, Martinez recalls driving through the Mississippi Delta at twilight, thinking that the place was "stained with so much blood of so many black people who just tried to register people to vote."

It was a time when fear begat fearlessness in people like Martinez, when civil rights workers witnessed the burial of many freedom fighters.

After that intense summer, Martinez became the director of the New York office of SNCC. She and fellow civil rights activist, Maria Varela, were the only Chicanas in a black movement with many white supporters. Martinez's main role at this time was to raise funds and to alert the media whenever people were arrested or jailed, reasoning that press coverage "might keep someone alive."

In 1965, Cesar and Helen Chavez and Dolores Huerta led an historic march of thousands of farmworkers from Delano to Sacramento, Calif. SNCC sent Martinez, who had been weaned on her father's stories about having seen Emiliano Zapata during the Mexican Revolution, to deliver a speech in solidarity with the United Farm Workers of America. For someone raised on the East Coast, she remembers how invigorating it was to be entirely among people who shared her own roots.

In 1966, aware of the uneasy race relations within the civil rights movement she wrote an article titled "Neither Black or White." Even back then, she identified a problem that Latinos today still observe: when it comes to the national discourse regarding racial issues in the United States, Latinos don't matter.

In 1968, she moved to Albuquerque to connect with the Chicano movement, specifically to support the land struggle of the Alianza Federal de Pueblos Libres (National Alliance of free Pueblos) in New Mexico. There, Martinez's mission was to help found the newspaper, "El Grito del Norte (The Cry of the North)." "I went for two weeks," she says, "and I stayed for eight years." El Grito went on to become one of the principal voices of the Chicano movement.

Before Martin Luther King, Jr's assassination in 1968, the farmworker's movement had also won the support of King. "The Chicano movement was indigenous to the Southwest [and Midwest], but it was definitely stimulated by the black civil rights movement," says Martinez.

In 1973, Martinez, along with many Chicano supporters, went to the siege at Wounded Knee, South Dakota, in support of the American Indian Movement. Dozens of AIM activists, along with local Oglala Sioux people, took over some buildings in the Pine Ridge reservation town, to draw attention to Indian grievances. During the siege, hundreds of federal agents, using military equipment, surrounded the protesters and the two sides exchanged gunfire.

Unlike the original siege of Wounded Knee in 1890, which resulted in the massacre of hundreds of Indians, the modern military siege ended peaceably. However, federal agents harassed AIM activists for many years to follow.

These movements were happening during a time when people's movements around the world were forcing dictators from power. "It was inspiring," says Martinez. But eventually, all the major protest movements were debilitated if not destroyed--some because of internal strife--but principally because of government infiltration.

In April, PBS will air a new documentary, "Chicano!" which focuses on the Chicano movement from 1965-1975. Martinez, who now lives in the San Francisco Bay Area, says that, unlike many, she does not believe that the movement died. The recent struggle against California's anti-immigrant Proposition 187 and the current fight to defend affirmative action prove that.

Martinez, along with author Elena Featherston, is currently on a national "Black & Brown-Get Down" speaking tour. Their message, she says, is "building black/brown alliances in an age of divide and conquer."

The message isn't just for African Americans and Latinos, says Martinez, but for everyone. One of the main lessons she has learned in life since that early bus ride is that you can't fight racism alone.