IN A corner of the immaculate lawn of Mt Nebo Missionary Baptist Church, in Philadelphia, Mississippi, lies a long tombstone adorned with fresh flowers. Nobody is buried there; the stone is a memorial to James Chaney, Andrew Goodman and Michael Schwerner, three young men who came to Neshoba County, of which Philadelphia is the seat, in the summer of 1964 to register black voters. On June 21st Klansmen allied with the county police stopped their car, shot all three at close range, and buried them under a dam.

Ten months before his death, on August 28th 1963, Goodman, then a student at Queens College in his native New York, heard the state where he would die described by Martin Luther King as “sweltering with the heat of injustice, sweltering with the heat of oppression”. He was one of hundreds of thousands who joined the March on Washington for Jobs and Freedom, the greatest demonstration of America’s civil-rights era, and heard King’s “I have a dream” speech delivered from the steps of the Lincoln Memorial.

The speech is remembered principally for its stirring rhetoric, in particular its vision of a future in which King’s children would “not be judged by the colour of their skin but by the content of their character.” At its core, however, is a simple, radical and, most important, correct argument. King explains that the demonstrators have come “to cash a cheque.” America’s constitution and declaration of independence were “a promissory note …that all men—yes, black men as well as white men—would be guaranteed the unalienable rights of life, liberty and the pursuit of happiness.” The demonstrators were asking merely for the rights guaranteed to all Americans by the country’s founding documents. Segregationists, therefore, were not just bullies and bigots; they were failures as Americans, because they misunderstood or ignored the country’s fundamental premise. King presented his dream, gloriously and specifically, as the American dream.

The promises of democracy

After 50 years, legal segregation is a distant memory, and race in America is not the unbridgeable chasm it once was. The country has a black president. The sort of comity that King evoked, in which the descendants of slaves and of slave owners “sit down together at the table of brotherhood”, can be found in many places, including the Deep South. The rate of marriage between blacks and whites is rising.

But America has not entered—as many hoped it would at the time of Barack Obama’s election—a “post-racial” phase. Blacks remain likelier than whites to lack jobs, be poor, get arrested and serve time in prison. Residential segregation of blacks from other races is declining, but still persists. After years of narrowing, the gap between black and white median income widened from 2000 and 2011, and the gap in household wealth is enormous. The work of the civil-rights era, it would seem, is not yet done. But the work has changed, and now it falls to different hands. The responsibility for ending segregation and repealing racist laws lay mainly with the government. Government’s role in narrowing the racial gaps that persist, though, is smaller and less clear.

King’s speech laid out four major grievances: discrimination by private businesses and local government; barriers that kept black Americans from voting; unfair treatment by police; and what might broadly be called social mobility and economic opportunity. “We cannot be satisfied”, King said, “as long as the Negro’s basic mobility is from a smaller ghetto to a larger one.”

The Civil Rights Act of 1964 directly addressed the first grievance. Signed into law by Lyndon Johnson ten months after the march, and 11 days after the murders of Chaney, Goodman and Schwerner, it was strongly opposed by southern members of Congress. It banned businesses that engage in interstate commerce (which the federal government has the authority to regulate) from refusing to serve members of the public on the basis of race; prohibited the denial of access to public facilities on the basis of race; authorised the attorney-general to sue local authorities to force school desegregation; banned discrimination by the recipients of federal funds on pain of losing that funding; and outlawed discrimination by any business employing more than 25 people, creating an Equal Employment Opportunity Commission (EEOC) to respond to complaints about such discrimination in the process.

The Voting Rights Act of 1965—which, though passed with strong bipartisan support, again faced bitter opposition from southern senators and congressmen—addressed King’s second grievance. It outlawed poll taxes, literacy tests and other practices designed to prevent blacks from voting. It gave the Justice Department and federal courts the power to veto proposed changes to voting procedures in jurisdictions with a history of discrimination.

The two acts had three large, lasting political effects. First, black political participation increased dramatically. In 1965 less than 7% of eligible black Mississippians, roughly 19% of eligible black Alabamans and around 32% of eligible black Louisianans were registered to vote. Congress had five black members, all representatives from northern and western cities. In 2012 the share of registered black voters in Louisiana, Mississippi, North Carolina and South Carolina exceeded that of non-Hispanic whites, and trailed it by only a little in most other southern states. In the last presidential election, black voter turnout exceeded that in any other racial category. Roughly one in ten members of the House is black; they come from 25 states and territories. Mississippi now boasts more black elected officials than any other state, though none holds statewide office.

Second, civil-rights legislation realigned America’s political parties. At the time of the march Democrats had a large and durable majority in the House of Representatives, a coalition between northern and urban liberals and southern segregationists (white southerners cleaved to the Democrats after losing the civil war to Abraham Lincoln, a Republican). The passage of civil-rights legislation broke that coalition. Strom Thurmond, a segregationist senator from South Carolina, switched parties in response to the 1964 Civil Rights Act; after him, the deluge.

During the Congress that passed the Civil Rights Act, the 11 confederate states had 128 senators and representatives; 115 were white Democrats. Those states today have 160 senators and representatives, of which just 22 are white non-Hispanic Democrats (see chart 1). When Johnson signed the Civil Rights Act into law, he reportedly told an aide that Democrats had “lost the South for a generation.” It has now been at least two generations, and despite some purpling at the edges, the South remains solidly Republican. And as white southerners—along with working-class whites from northern cities, once called “Reagan Democrats”—moved to the Republican Party, most of the blacks in the party of Lincoln left. This has let Democrats take black voters for granted and Republicans ignore them, a problem which has been exacerbated by the creation of “majority-minority” seats which contain a disproportionate number of black voters.

The bank of justice is bankrupt

Third, civil-rights legislation dramatically boosted the federal government’s power to enforce the 14th and 15th amendments, which promise all citizens, regardless of race, the right to vote and “equal protection of the laws”. They were passed after the civil war, and the South had spent the better part of a century violating them. With enforcement power came not only increased federal reach but also expanded federal bureaucracy. The EEOC has grown from an agency with roughly 100 employees and a $2.25m budget in 1965 ($16.4m in 2012 dollars) to one with 2,346 employees and a $360m budget in 2012. In 1965 Johnson signed an executive order barring racial discrimination in federal contracts. The Office of Federal Contract Compliance Programs, created to police those requirements, now enforces pro-black racial preferences. It has a $105m budget and about 750 full-time employees.

Measured against its condition at the time of King’s speech, black America’s progress has been remarkable. In 1959 55.1% of blacks lived in poverty and just 4.6% of blacks between 25 and 29 had graduated from college. In 2010 38% of blacks between the ages of 18 and 24 were enrolled in a university, and most black Americans are not poor. Yet measured against other American ethnic groups black progress looks less impressive. Blacks lag behind whites in life expectancy and median income (see chart 2); they exceed whites in dropout and poverty rates. The income disparity, in fact, is growing. The gap in median individual income between blacks and non-Hispanic whites rose by a third, to almost $9,000 a year, between 2000 and 2011. But that is trifling compared with the wealth gap. The bursting of the housing bubble took a far greater toll on black families than whites, reducing their median wealth, according to a Pew Research Centre study, by 53% between 2005 and 2009 (when adjusted for inflation). Over the same period white median wealth fell by just 16%. In 2009 more than one-third of black households had zero or negative net worth, compared with 15% of white households. In 2011 the median household wealth (comprising cash, investments, homes, cars and other assets) for America’s white families was $110,500. For blacks it was $6,314 (Hispanics were similarly badly off). A separate study by the Urban Institute found that between 2004 and 2010 blacks lost 23% of their average wealth, while whites lost 1%. Being poorer, black children are more likely to attend substandard schools, and less likely to graduate from college, than whites. This depresses future earning power, and keeps blacks over-represented in jobs that offer no benefits or retirement plans. They have less money to put towards home-ownership, and homes account for the largest share of wealth for both black and white families. Thus low wealth perpetuates itself. On average white families buy homes eight years earlier, and tend to be able to put down more money, thus lowering interest rates and mortgage payments. Residential segregation—sometimes but not always a matter of choice—means that many blacks live in areas where homes are worth less, and accrue value more slowly, than homes elsewhere. Because they tend to be more recent homeowners with higher-risk mortgages, blacks are more vulnerable to foreclosure. All of this makes black prosperity more precarious. A paper by Bhash Mazumder, an economist at the Chicago Fed, found that roughly 60% of black Americans whose parents had an above-average income fell below the average as adults. The figure for whites was 36%.

America’s over-punitive criminal-justice system also stymies black accumulation of wealth, as well as social mobility. In 2011, 478 of every 100,000 white men and 51 of every 100,000 white women were imprisoned. For black men the rate was 3,023 per 100,000 and for black women 129 per 100,000. This disparity cannot simply be put down to differences in crime rates: blacks are often more likely than whites to be arrested for the same crime. Young whites and blacks use marijuana, for instance, at roughly the same rate, but across the country blacks are almost four times more likely to be arrested for marijuana possession, according to the American Civil Liberties Union; in some places their arrest is over eight times more likely. People with criminal records risk losing public benefits, being kicked out of public housing and suffering permanent gaps in employment and earning prospects.

Children stripped of their selfhood

The dissolution of the black family may do more harm to black mobility than any other single factor. Marriage is declining and out-of-wedlock births are increasing across American society. Black Americans lead the way in both. In 2011 72% of black babies were born to unwed mothers, and just 29% of black adults were married, compared with 60% in 1960. Conservatives tend to blame welfare policies, and liberals the lack of low-skill, living-wage jobs, for the decline of black marriage. Either way it has left black women as principal breadwinners in a large number of homes with children. A National Women’s Law Centre study found that in 2011 black women who worked full-time earned, on average, 64 cents for every dollar a white man earned. But among black married couples with children, women are almost twice as likely to outearn their husbands as to be outearned by them.

Still, most black children are no longer brought up in two-parent homes: in 2011 55% of black children were being raised by a single parent. Such children are four times more likely to be poor than children raised by their married parents. Ron Haskins and Isabel Sawhill, of the Brookings Institution, have found that people who finish high school, work full time and wait to have children until they are married and 21 or older have a 72% chance of joining the middle class and just a 2% chance of being poor. The numbers are reversed for those who violate all three rules.

The roots of many of these problems lie in the legacy of slavery and segregation. But the important question is not where they came from, but how to ameliorate them now. The era of race-conscious law appears to be drawing to a close. Last June the Supreme Court invalidated an important clause of the Voting Rights Act, leaving its future uncertain. The court also set a higher bar for universities that want to use affirmative action, which several states have already outlawed.

Some have called on Mr Obama to “do more” for black Americans—but their calls tend to be longer on sentiment than substance. Nor are they warmly received. While 95% of black Americans in 2008 and 93% in 2012 voted for Mr Obama, his relationship with other black leaders is often fractious. Cornel West, a professor and commentator, has called him “a black puppet”. Mr Obama told members of the Congressional Black Caucus to “stop complaining, stop grumbling, stop crying.” He used his first widely seen national address—to the Democratic National Convention in 2004, when still an Illinois state senator—to urge black Americans to “eradicate the slander that says a black youth with a book is acting white.” That stereotype seems to be particularly harmful to black students. Roland Fryer, an economist at Harvard, found in a study published in 2005 that the popularity of white schoolchildren tends to increase in tandem with their academic results: the better they do in school the more friends they have. For black and Hispanic pupils, the opposite is true. Mr Fryer found this effect especially prevalent in schools that are less than 20% black, less prevalent in schools that are predominantly black and almost non-existent in private schools. But unlike previous barriers to black progress, that posed by the “acting white” stereotype is neither imposed from the outside nor codified in law. The principal problem that black Americans faced for much of their country’s history was not that some people disliked them or thought them inferior; it was that the people who disliked them and thought them inferior had the power to write laws making them second-class citizens. That is no longer the case. As Mr Obama told a class graduating from Morehouse College, a respected and historically-black university, “Whatever you’ve gone through, it pales in comparison to the hardships previous generations endured—and they overcame them. And if they overcame them, you can overcome them, too.”

The true meaning of its creed

Discrimination has not vanished: the recent decision in New York to outlaw stop-and-frisk searches reflects the fact that in many places the police remain far more likely to suspect and harass innocent blacks. Voter-ID laws, while no doubt rooted in partisan rather than explicitly racial motives, still place a far heavier burden on minority voters than on white ones.

But the Mississippi that took the lives of James Chaney, Andrew Goodman and Michael Schwerner is, mercifully, gone. The state may not yet be the “oasis of freedom and justice” of King’s dream, but in front of the Williams Brothers general store—which probably looks much as it did when it opened more than 100 years ago—black and white Mississippians mix easily and naturally. A few kilometres east of Williams Brothers sits the Neshoba County library, one of the stopping places on the 1966 March Against Fear from Memphis, Tennessee to Jackson, Mississippi. The march was started by James Meredith, the first black man admitted to the University of Mississippi; he was shot and wounded soon after leaving Memphis, and King and others took up the baton. It was King who spoke to the crowds at the Neshoba library.

A few blocks from that library is City Hall, where James Young, Philadelphia’s mayor, has his office. In 2009 Mr Young became the first black mayor ever elected in majority-white Philadelphia. He was re-elected earlier this year.