AUGUST WILSON was not only the finest black dramatist America has yet produced but a dramatist whom posterity may well rate alongside Eugene O’Neill and Arthur Miller as one of his nation’s most important. The cycle of plays for which he will be remembered — each set in a different decade of the 20th century, each chronicling a particular aspect of Afro-American history — combines subtlety and weight, humour, pathos and a profound sympathy for small, seemingly insignificant people trapped by forces they seldom understand and usually are powerless to resist, let alone overcome.

Wilson was born Frederick August Kittel in 1945 and was actually of mixed race, his mother being a black cleaner and his father, whom he remembered as “a sporadic presence” who eventually succumbed to alcoholism, a baker of German descent. It was not an unhappy upbringing. The family lived in Pittsburgh, the city where Wilson was to set many of his plays, and, he later said, life was emotionally if not financially “rich”. The young Freddie, who was darker-skinned than his siblings, went to an overwhelmingly white Catholic school, only to encounter the prejudice that ended his formal education at the age of 15 and convinced him that he belonged to the black community.

Again and again he found notes on his desk reading “nigger, go home”. And when a teacher refused to believe that he himself had researched and written an essay on Napoleon, he walked out and, while pretending to his mother he was still at school, spent his days doing serious reading in the Pittsburgh Public Library. There he encountered the work of James Baldwin and other Afro-American writers and, taking jobs as a dishwasher, gardener and delivery boy, began to write poetry. He changed his name to August Wilson and, he said, “dreamed of being part of the Harlem renaissance”.

He had seen no mainstream drama at all when he and a fellow Pittsburgh poet founded the Black Horizon Theatre Company in 1968, and at first he wrote angry, avant-garde plays in verse. It was not until the late 1970s that he found his true voice, producing early versions of the realistic Jitney and Ma Rainey’s Black Bottom, and it was only in 1984 that he had his first success. That was when Yale Rep staged Ma Rainey, a production that transferred to Broadway, where it ran ten months and won him the first of many awards, the New York critics’ best-play prize.

Most of Wilson’s plays were introduced to the UK by Kilburn’s Tricycle Theatre, but Ma Rainey and Jitney received their British premieres at the National Theatre and both show his distinctive qualities as a dramatist. Jitney, which is set in the 1970s, is reminiscent of Sean O’Casey’s portrayals of Dublin slum-dwellers in its generous, incisive picturing of the motley mix of Afro-Americans who work for a minicab firm that goes to areas of Pittsburgh that make other cab-drivers jittery. Ma Rainey, representing the 1920s, occurs in a studio where the legendary title-character is making a recording, but she is secondary in importance to the musicians in her band, whose interlocked lives reflect the pain, pathos and power of the blues they are playing. As John Lahr wrote in The New Yorker, Wilson’s work “paints the big picture indirectly, from the little incidents of daily life ”.

White Americans are seldom so much as mentioned in his plays, but the impact of an uninterested, uncaring and sometimes hostile white America is unmissable. That is the case with the two plays which won him Pulitzer Prizes, in 1987 and 1990 respectively. Fences reflects Pittsburgh’s racial tensions in the 1950s, involving as it does a character partly based on his mother’s second husband, a promising athlete who served 23 years for killing a man during a bungled robbery. The Piano Lesson, which is set in the 1930s, involves a young man who returns to the same city to buy the land where his ancestors worked as slaves.

The memory of slavery, conscious or buried, marks much of Wilson’s work. “Blacks in America want to forget about slavery,” he once said. “The stigma, the shame. But if you can’t be who you are, who can you be? How can you know what to do?” That belief helps to explain why his plays have sometimes been criticised as didactic “victim drama”; but the answer to this accusation is that they and their characters come abundantly, unsentimentally and often quirkily to life in the theatre. In Two Trains Running, set in a tacky Pittsburgh diner after the deaths of Martin Luther King and Malcolm X, the characters include a former crap-game runner who has become wealthy from selling coffins to families bereaved by black-on-black murders, an ex-con who offers the mortician his services as a driver with a proud “I drove a getaway car once”, and a bum known as Hambone, since he was once cheated of a ham promised him for painting a fence and now blunders about wailing “give me my hambone”.

Wilson did not avoid controversy, declaring that the effects of the migration north by freed slaves had been malign and that “integration”, so-called, had lessened black self-sufficiency and the chance of black self-improvement.

In particular, he lamented the erosion of what he called a “warrior spirit” in Afro-Americans. This is memorably illustrated in the most recent of his plays to be premiered in Britain, King Hedley II, whose protagonist is a sort of frustrated medieval knight or repressed African chieftain not long out of prison for murder and now reduced to selling stolen fridges in the hope of raising the money to open a video shop.

Wilson’s 2003 play Gem of the Ocean, which is set in 1904 Pittsburgh and has among its characters a former slave who survives by scraping excrement from pavements, opens at the Tricycle Theatre on January 6, 2006. Radio Golf, the last of the ten plays in his 20th-century cycle, was staged last spring at Yale Repertory Theatre.

Wilson was married three times: in 1969 to Brenda Barton, becoming estranged and eventually divorced from her when she joined the Nation of Islam; in 1981 to Judy Oliver, from whom he was divorced in 1990; and in 1994 to Constanza Romero, a Colombian-born costume designer who survives him, as do his two daughters by his first and third marriages.

August Wilson, playwright, was born on April 27, 1945. He died on October 2, 2005, aged 60.