Park Street is quiet today. I walk past neat, sun-baked lawns and rows of houses, the Stars and Stripes waving from porches. One house has an "Obama for President" sign in the front window.
On 4 September 1957, this street in Arkansas's state capital, Little Rock, was noisy, crowded and charged with an atmosphere of violence. Nine young black students were about to start at the previously all-white Little Rock Central High School, an impressive-looking building just across the road from where I'm standing. They were met with a thousand-strong mob of angry white locals and soldiers from the Arkansas National Guard, who barred their entry to the school with bayonets. The crisis that followed became one of the most important events in the history of the civil rights movement.
I'm guided around this National Historic Site by Spirit Trickey, daughter of Minnijean Brown Trickey, one of the "Nine". Fifty years after her mother attended Central High, Spirit is back here working as a park ranger for the school and its excellent museum. She paints a vivid picture of what took place.
Arkansas was one of several Southern states that refused to accept a 1954 Supreme Court ruling that schools be desegregated. Its conservative governor, Orval Faubus, called in the Arkansas National Guard for the black students' first day at school under the pretence they would keep the peace - in fact, they had orders to block them from entering.
President Dwight D Eisenhower moved (many say reluctantly), sending federal troops to enforce integration. The 101st Airborne Division set up camp in the sports stadium behind the school and, after weeks of legal wrangling, the black students began attending Central under military protection. This was a make-or-break situation - had Eisenhower not intervened, the black students would have been forced to return to segregated schools, as happened elsewhere, a victory that would have emboldened racists across the country to resist change.
We enter the school and walk the empty corridors where the black students were tormented daily. White students called them names, threw food, pushed them down stairs. One, Melba Patillo, had acid sprayed in her eyes. "They had soldiers to protect them," Spirit explains, "but soldiers couldn't go into bathrooms, changing rooms, classrooms. There were about a hundred kids who made it their mission to make the Little Rock Nine's lives miserable."
In the cafeteria hall, Spirit tells the "chilli incident" story. Her mother, Minnijean, was carrying her tray of food back to a table when some white boys kicked out their chairs and refused to let her pass. When they kicked her legs again, Minnijean "dropped" her plate of chilli on one of them. A soldier from the 101st rushed her to safety. She was suspended for six days. Two months later, after being assaulted by a group of girls, Minnijean retorted, "Leave me alone, white trash." A teacher saw; Minnijean was expelled. Cards were passed among the white students saying "One down, eight to go".
Ernest Green, the only senior of the Nine, was the first black student to graduate from Central High. The army had to spread soldiers throughout the grounds for the ceremony (attended by the then relatively unknown Martin Luther King). Ernest walked across the stage to receive his diploma even though he had received bomb and death threats.
Governor Faubus closed Little Rock's public high schools the following year rather than desegregate them, and the eight remaining black students went on to graduate elsewhere. But when schools, including Central High, reopened in 1959 they did so under a statewide system of integration.
Arkansas remains a conservative state, though there are liberal pockets, such as the bohemian town of Eureka Springs. Of the state's 75 counties, 43 are "dry", or alcohol-free. Churches line the roadside. The area is also home to The Great Passion Play, a hugely popular outdoor staging of Christ's last week on earth, and the Creation Truth Foundation's Earth History Museum.
The 1957 crisis continues to be a big part of the state capital's identity. People around the world know Little Rock for two things, says Spirit: Bill Clinton and the Little Rock Nine.
Central High itself has changed, however - the student intake for 2007/2008 was 50 per cent black, 46 per cent white and 4 per cent "other". But, says Spirit, "Central isn't exempt from the problems that stem from our recent history. To come out of something that was systematically implemented - legal segregation - you see the residual effects in any school in America." According to young people she does outreach work with, Central's cafeteria is still divided into areas: black, white and mixed.
I drive across town to look at Testament, a memorial sculpture unveiled in 2005 on the lawn of the Arkansas State Capitol. Beside the statues of black students carrying their schoolbooks are plaques bearing inscriptions. "We wanted to widen options for ourselves, and later for our children," says Ernest Green.
Given what they endured to expand options for themselves and future generations, what do the Little Rock Nine think about the fact that, just 50 years later, there is the possibility of a black president? "This is something they maybe never envisioned in their lives," says Spirit. "To me, it shows change is taking place."
Spirit appreciates what a historic moment this is. "My great-grandmother was a slave. My mother was blocked from getting an education because of the colour of her skin. I feel fortunate to be in a time and place where a black candidate is possible." Her optimism is tempered by pragmatism, however. The race problems of 1957 haven't disappeared. In Arkansas, she says, "like many parts of America, segregation still exists - not just in schools, but in neighbourhoods and communities". The possibility of a black president is, like the integration of Central High, a step, not a job done.