One measure of the progress that has been made is that the commemorations today to mark the 30th anniversary of Martin Luther King's assassination have been overshadowed by demands for an inquiry into claims that he was the victim not of a solitary gunman, as the authorities have always maintained, but of a sinister conspiracy involving the mafia and the FBI.
On the anniversary of what Jesse Jackson calls Dr King's "crucifixion" it has been traditional to evaluate the martyr's legacy in terms of America's failure to live up to his dream that one day people would be judged not "by the colour of their skin but the content of their character".
But Coretta Scott King, Dr King's widow, and Andrew Young, the black former United States ambassador to the United Nations, have shifted the emphasis this last week, leading a clamour for a re-opened investigation into the circumstances of the assassination and the possible cover-up that followed. Mrs Scott King has called for a commission of inquiry that would grant immunity to those who came forward with evidence of a conspiracy. Mr Young - in his day one of Dr King's more visible disciples - has gone so far as to propose that James Earl Ray, who is serving a 99-year jail sentence for the murder but claims he is innocent, should be granted clemency.
"Nobody is interested in retribution, not even justice," Mr Young told the Atlanta Constitution. "We are interested in extending the mercy of the family and the movement to people like James Earl Ray, who regardless of his role was an innocent victim of the racism that was going on at the time."
While formally the commemorative speeches today in Memphis, Dr King's "Calvary" (again according to Jesse Jackson), will indeed dwell on racism and justice, the underlying theme will be more "whodunnit?" than "whodunnusin?"
Which is not to say that the race question is likely to go away any time soon. In America it remains an obsession. But a glance at developments in Memphis in the last 30 years does tend to refute the view of black radical leaders who insist on maintaining that Dr King's work was in vain.
The reason Dr King made his fateful visit to Memphis in the first place was to denounce the appalling working conditions of the city's black sanitation workers. The Rev Samuel Billy Kyles, a local minister who stood at Dr King's side seconds before he was shot, said he hoped participants in today's scheduled march, rally and prayer vigil would note the advances that have been made.
Today Memphis has a black mayor, a black member of congress, a black head of the local school system and a black police chief. "I went to jail in 1962 for riding in the front of the bus," Mr Kyles told the New York Times. "Now the chairman of the trustees board of my church is the general manager of that same bus company."
Memphis is no lone beacon of black advancement. Big American cities such as Dallas, Houston, Seattle, St Louis, San Francisco, New York, Washington, Denver have elected black mayors, even though in many cases their constituencies have been predominantly white.
In 1970 the US had a total of 1,469 black political office holders. Twenty- five years later the number had climbed to 8,406. Colin Powell, America's top military man during the Gulf War, would have beaten Bill Clinton in the 1996 presidential election, according to the evidence of the polls.
In the lower strata of society the statistics remain bleak, however, as the disproportionate figures for black poverty and black imprisonment reveal. And while crass expressions of white racism are now rare, racial mistrust continues to fester like a sore. According to an eloquent set of statistics published by the Economist last year, the rate of inter- racial relationships between men and women is about 10 times higher in Britain than in the US
Trevor Phillips, page 23