Strictly speaking, Rosa Parks' gesture of defiance on the evening of 1 December 1955 does not mark the beginning of the civil rights struggle that consumed America for the subsequent decade. That distinction belongs to the 1954 Brown v Board of Education ruling, ordering the desegregation of schools.
In fact, she was not even the first black woman to be arrested for refusing to surrender her seat on a bus. In March and October that same year, Claudette Colvin and Mary Louise Smith respectively were arrested and punished for doing the same.
But Ms Parks' arrest was different. She was a demure and modest woman, but possessed of a will of steel. She was also married to an activist in the National Association for the Advancement of Coloured People (NAACP), the oldest and most venerable US civil rights movement, where she gained a reputation as a militant for her efforts to boost black voter registration.
Her arrest gripped the country's imagination and galvanised the emerging civil rights movement. There followed a 380-day boycott of Montgomery buses by the city's blacks, organised in part by a young pastor newly arrived at the city's Dexter Avenue Baptist Church, named Martin Luther King. The eventual triumph came nine years later, when President Johnson signed the 1964 Civil Rights Act. But the small protest of Rosa Parks was the spark that lit the fire.
On Monday, aged 92, she died, venerated as little less than a 20th century saint. "A true American hero," Senator Edward Kennedy called her. "She sat down in order that we all might stand up - and the walls of segregation came down," said Jesse Jackson, the civil rights leader.
Death was probably a merciful release. She was frail and suffering from dementia, and had hardly appeared in public for a decade. But her impact has been enduring; indeed it may be measured by the career trajectory of another black daughter of Alabama, who has risen to heights of which Rosa Parks could not have imagined 50 years ago.
Three days before she died, Condoleezza Rice, the first black woman to become Secretary of State, returned to her home state and the city of Birmingham, 100 miles north of Montgomery, where she was born. Elegant and immaculate, she was feted at every stop like a rock star - or rather like an aspiring Presidential candidate that, despite repeated denials, some people are convinced she is.
Ms Rice's message was diplomatic, as she repeatedly compared the struggle for democracy in Iraq with the long struggle of blacks to throw off Jim Crow. But it was also a conscious statement of what black Americans could accomplish, when given the chance. But that chance would never have been possible without the peaceful revolution inspired in part by Rosa Parks.
The 42-year-old seamstress paid dearly for her effrontery. She and her husband lost their jobs. Hate callers threatened to kill her, and white supremacists firebombed the homes of her supporters. In 1957, she moved to Detroit - belatedly joining America's great internal migration of the first half of the 20th century, when millions of blacks left the segregated, jobless south and moved to the new industrial cities of the north where work was plentiful and minds less closed.
From there, she watched the landmark events of the campaign for civil rights unfold. That 1957, President Eisenhower sent federal troops to enforce the desegregation of Little Rock's Central High School. Three years later, four black students in Greensboro, North Carolina, staged a non-violent sit-in at a Woolworths cafeteria counter after white waitresses refused to serve them.
In 1961, came the first "Freedom Riders," as students made bus trips to test recent laws banning the segregated travel that had led to Ms Parks' arrest.
Sometimes they were met by howling white mobs. Slowly however, the cause advanced. That October, James Meredith became the first black student to enroll at the University of Mississippi, protected by 5,000 federal troops sent in by President Kennedy.
But the turning point was 1963, and the focal point Ms Rice's home town of Birmingham. That April, Dr King was arrested for promoting non-violent protest, and wrote his "Letter from Birmingham Jail," in which he argued that individuals had the moral duty to disobey unjust laws.
As unrest grew, Birmingham's Commissioner for Public Safety, the racist Eugene "Bull" Connor, turned dogs and firehoses against the demonstrators. The images drew outrage in the US and around the world, only strengthening the civil rights' cause.
On 28 August 1963, more than 200,000 people - far more than expected - joined the "March on Washington" that culminated in the "I Have a Dream" speech delivered by Dr King from the steps of the Lincoln Memorial.
All the while there was violence. Birmingham, probably the most segregated city of all, became known as "Bombingham".
Across the south, Ku Klux Klansmen terrorised neighbourhoods, while whites who rallied to the black cause were denounced as "nigger-lovers", beaten up, and sometimes murdered. But no single incident was viler, and none had more impact, than that on 15 September 1963 in Birmingham, at the 16th Street Baptist Church.
At 10.22am, a bomb placed by Ku Klux Klan members exploded. It was a Sunday, and the blast was timed to co-incide with the main morning service. Instead, the bomb killed four little girls, aged between 9 and 11, who were attending Sunday school in the crypt below the sanctuary.
Congress, the federal government, the entire world, even the American south, were stunned by the atrocity. President Kennedy was assassinated that November, but on 23 January 1964 the 24th amendment of the US Constitution took effect, banning the poll tax used in 11 southern states to obstruct black voting rights. On 2 July 1964, President Johnson signed the Civil Rights Act, the most sweeping of such legislation since Reconstruction, outlawing racial discrimination of every kind.
Last weekend, in a moving ceremony in the park opposite the 16th Street church, Birmingham paid formal homage to the four little girls, installing Addie Mae Collins, Denise McNair, Carole Robertson and Cynthia Wesley in the city's Gallery of Distinguished Citizens. One of the speakers was Condoleezza Rice - who was personally touched by those murders of 42 years ago.
"Denise McNair was my friend," she told the 200 dignitaries gathered on a bleak, chilly morning. "We were children together, we played together. When I think of the four, I think of them like that, just little girls growing up, going to Sunday school at a time when America was experiencing terrorism of the worst sort. What would they be doing today had they lived. They were near my own age - in that sense, I'm just one of many."
Today, beyond argument, the state once run by the arch-segregationist George Wallace has been transformed, physically and spiritually. The narrow one storey "shotgun" houses and tawdry apartment blocks around the church in Birmingham, where black families used to live have gone. The area is now part of an expanding and thriving downtown.
Old "rust belt" Birmingham, named after the English city because of its iron and steel industry, is now home to high-tech industries and a glistening new university medical complex that is Alabama's biggest single employer. A black mayor sits in Birmingham's City Hall, a black now heads the city police department that used to set dogs on protesters, and a black leads the fire department that once turned high pressure hoses on people seeking their most elementary rights.
The mood has changed too. "Thank you Birmingham, for having a heart so loving and kind," Cynthia Wesley's adopted sister Shirley said at the ceremony - words that could never have been spoken by a black woman living there in Rosa Parks' day. And then there was Ms Rice herself, proof of the American dream, but speaking in a city that half a century ago was symbol of another America, the one where there was no limit to the indignities inflicted on citizens whose skin was a different colour.
In one way, Condoleezza Rice is a special case, the product of a driven middle class family that prized hard work, learning and self-advancement, part of a civilised and cultured black enclave that somehow existed outside the Jim Crow universe. But her ascent would have been impossible 50 years ago.
Even so, the picture is far from perfect. In some measure, the US has overcome what she terms its "birth defect" of race. But de facto segregation persists. Almost every city has its black neighbourhoods. In Washington, the north-west quadrant of the city is overwhelmingly white while the north-east and south-east are overwhelmingly black - two worlds that co-exist but have not merged.
Or take the elementary school in Birmingham attended by Ms Rice when she knew Denise McNair. Then, it was the Graymont Coloured School, today it's the Brunetta C Hill Elementary School, a state school supposedly integrated yet with only two non-black pupils among the 248 students.
"Birmingham has come a long way, and Birmingham has worked very hard to overcome its past," Ms Rice said last weekend, in words which could be applied to the entire country. "But the work is never done. Race is part of the US heritage, and will remain so. I hope one day we'll be completely colour blind, but we're not there yet." And indeed, almost every social indicator shows that while blacks now live longer, better, and richer lives than they did in the 1950s, they lag well behind whites. By some measures the gap is widening, not narrowing.
Nor did the Civil Rights Act expunge race from US history. Frustrated by slow progress and unkept promises, a new breed of black militants emerged.
In 1967, the Detroit to which Ms Parks moved was torn part by race riots. A year later Dr King was assassinated in Memphis, sparking riots in many American cities. In 1992, black Los Angeles exploded after four white police officers were acquitted of beating up the black motorist Rodney King. In 1995 however it gained revenge of a kind when a black-dominated jury acquitted OJ Simpson of murdering his white wife, in the most racially-charged trial of the decade.
One wonders now what Rosa Parks made of it all. Shy and quiet-spoken, she was uncomfortable with the beatification thrust upon her, and with her place in the civil rights pantheon alongside the likes of Dr King and Nelson Mandela. But she was surely no less determined than they to see the unfinished struggle through.Reuse content