During the presidential campaign, Barack Obama stunned many by attacking African Americans in ways that would have jeopardized the career of any white politician. He mocked blacks named “ Pookie,” “Ray-Ray,” and “Uncle Jethro” who feed their children cold Popeye’s fried chicken for breakfast, sit on the couch watching ESPN, don’t read books, let their children roam the streets, and are “ acting like boys instead of men.”

In A Renegade History of the United States, I argue that this bashing of blacks has its roots in the assimilationist politics of the Civil Rights Movement, which required that African Americans embrace the Protestant work ethic, sexual repression, and the nuclear family—norms that had been created by white Europeans and Americans and which were alien to Africans before they were brought to America as slaves.

In the summer of 1957, a Baptist preacher in the segregated South issued a series of fiery sermons denouncing the laziness, promiscuity, criminality, drunkenness, slovenliness, and ignorance of negroes. He shouted from pulpits about the difference between doing a “real job” and doing “a Negro job.” Instead of practicing the intelligent saving habits of white men, “Negroes too often buy what they want and beg for what they need.” He said that blacks were “thinking about sex” every time they walked down the street. They were too violent. They didn’t bathe properly. And their music, which was invading homes all over America, “plunges men’s minds into degrading and immoral depths.”

King recognized that black sexuality posed a special threat to his assimilationist project. “We must walk the street every day, and let people know that as we walk the street, we aren’t thinking about sex every time we turn around,” he told one audience.

The preacher’s name was Martin Luther King, Jr.

In his sermons and writings, King called for African Americans to work hard, to shun immoral forms of sexuality, and to curb their materialism. They would no longer abdicate familial and social responsibilities and would undergo “a process of self-purification” to produce a “calm and loving dignity befitting good citizens.”

In 1957 King cemented his position as national spokesman for civil rights with three interlocking projects: the founding of the Southern Christian Leadership Conference, the launching of a voting-rights effort called the Campaign for Citizenship, and an evangelical crusade to rid black people of un-Christian and un-American habits. The first two projects have been noted by historians as marking King’s ascendancy to leadership of the civil-rights movement. What is remarkable, however, is the almost complete silence among chroniclers of King’s career on his moral reform crusade among African Americans.

In the summer of 1957, King delivered a series of sermons under the title, “Problems of Personality Integration.” The sermons were clearly intended to prepare African Americans for entry into mainstream American culture. King encouraged “those who are giving their lives to a tragic life of pleasure and throwing away everything they have in riotous living” to “lose [their] ego in some great cause, some great purpose, some great ideal, some great loyalty.” By doing so, King said, they would create in themselves what he called “the integrated personality.”

In subsequent speeches, as well as in an advice column he began writing for Ebony in 1957 and in a book he published the following year, King endorsed Christian self-abnegation as a means to attain “first class citizenship.” To become citizens, African Americans must “seek to gain the respect of others by improving on our shortcomings.” King called for blacks to stop drinking and gambling and to curtail their desires for luxuries. On the causes of black crime, he blamed not only poverty and structural racism but also the lack of discipline and morality in the ghetto. “The church must extend its evangelistic program into all of the poverty-stricken and slum areas of the big cities, thereby touching the individuals who are more susceptible to criminal traits. By bringing them into the church and keeping them in touch with the great moral insights of religion, they will develop more inner stability and become more responsible citizens,” King wrote.

King even attributed poverty in large measure to what he considered the profligacy and laziness of African Americans. On these issues he approvingly paraphrased Booker T. Washington: “There is a great deal that the Negro can do to lift himself by his own bootstraps. Well has it been said by one that Negroes too often buy what they want and beg for what they need. Negroes must learn to practice systematic saving.” King was particularly concerned that African Americans had rejected the white work ethic:

"Don’t set out to do a good Negro job. [We] must head out to do our jobs so well that nobody could do them better. No matter what this job is, you must decide to do it well. Do it so well that the living, the dead, or the unborn can’t do it better. If it falls your lot to be a street sweeper, sweep streets like Raphael painted pictures; sweep streets like Michelangelo carved marble; sweep streets like Beethoven composed music; sweep streets like Shakespeare wrote poetry; sweep streets so well that all the host of heaven and earth will have to pause and say: ‘Here lived a great street sweeper, who swept his job well.’ " King recognized that black sexuality posed a special threat to his assimilationist project. “We must walk the street every day, and let people know that as we walk the street, we aren’t thinking about sex every time we turn around,” he told one audience. In Ebony he impugned readers to avoid rock 'n' roll, which “plunges men’s minds into degrading and immoral depths.”

When white southerners spoke of African Americans in these terms, they commonly referred to “bad niggers.”

As the civil-rights movement ebbed by the middle of the 1960s, black social scientists and civil-rights leaders grieved over the failure of the movement to conform its constituents to the American family ethic. In 1965, C. Eric Lincoln argued that “true integration” could not “be achieved until the nation—and the Negro—solves a crucial and immediate problem: how to ‘Americanize’ the fragile, fractured Negro family.” In the same year, Kenneth Clark, the author of the NAACP’s argument in the Brown case that segregation “damaged” the black psyche, lamented that the death of legal segregation did not reverse the emasculation of the black male and the rise of the “pathological” black family. Slavery, discrimination, and poverty “made the female the dominant person in the Negro family,” Clark wrote. “Psychologically, the Negro male could not support his normal desire for dominance.”

King echoed these sentiments in his last major publication, Where Do We Go from Here: Chaos or Community? which appeared in 1967. Agreeing that slavery, segregation, and enforced poverty had removed the black man from his proper role, King saw little improvement in the black family, which he called “fragile, deprived and often psychopathic.” With dimming optimism, King hoped that the cultural reformation of African Americans would help bring them into what he called “The World House.” Historians have yet to acknowledge what King well understood, that a great many personal freedoms were included in the price of admission to that house.

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Thaddeus Russell is the author of the forthcoming A Renegade History of the United States (Free Press/Simon & Schuster, 2010). He teaches history and cultural studies at Occidental College and has taught at Columbia University, Barnard College, Eugene Lang College, and the New School for Social Research.