Lanford Wilson, a playwright who emerged out of the scrappy Off-Off-Broadway scene to compose humane, lyrical dramas of American life that played on Broadway and in theatres around the world, died March 24 2011 after an illness, his longtime director Marshall W. Mason told friends and colleagues via Facebook.

"Our great writer and my closest friend passed away this morning at 10:45," Mason wrote. "The doctors say it was a peaceful, painless end. I'm very happy that just a couple of days ago Jeff Daniels and Jon Hogan serenaded him in his hospital room…. Words cannot express the loss we all will feel, but we must be grateful for the bountiful beauty he bestowed upon us."

Mason said that Mr. Wilson died complications from pneumonia, in a long-term acute care hospital in Wayne, NJ, after a lengthy stay at New York Presbyterian Hospital.

Mr. Wilson's work was first seen in such bohemian, downtown dens as Caffe Cino and Cafe LaMaMa E.T.C. His youthful colleagues at that time of artistic revolution included writers Sam Shepard, Leonard Melfi, John Guare and Jean Claude van Itallie. He said the best advice he ever received was from Cino: "Do what you have to do."

"We had such a great apprenticeship at Cino and La Mama and Judson Church," he remembered years later. "So many of the writers were so prolific; we were writing constantly, since shows were 30-40 minutes long and ran for a week. We got in the habit of writing and writing rapidly. So Sam Shepard and John Guare — a bunch of us actually — became writers. And shows were rarely reviewed, so we were doing it for ourselves. We once did Home Free, no one showed up. Joe said 'do it for the room,' and we did it for Joe and me and Marshall Mason. And it was a damn good performance."

In 1969, with Cino dead, he created his own artistic home. He was one of four founding members of the Circle Repertory Company, a troupe dedicated to a policy of company playwrights writing for company actors. The theatre became an influential Off-Broadway hothouse of talent during the 1970s, and it was there that many of Mr. Wilson's significant works debuted, including The Hot l Baltimore, Fifth of July and Talley's Folly. Most were directed by Circle Rep co-founder Mason. Together the two men formed one of the most formidable playwright-director teams in the annals of American theatre. (An amateur graphic artist, Mr. Wilson also did all the posters for his shows at Circle Rep.)

Mr. Wilson won the Pulitzer Prize for Talley's Folly, one of his mildest works, and the central and most famous play in his "Talley Trilogy," which tracked the adventures of different generations of the same Missouri clan. Fifth of July — set in 1977 among a group of friends disillusioned by the atrophying forces that overtook their lives in the years following the social upheaval of the 1960s — came first. "I wanted to write about my Berkeley friends, who had retreated into protective shells after their disenchantment with the sixties," Wilson said.

In contrast to the crowded Fifth of July, Talley's Folly was a warm-hearted pas de deux, set in 1944, between Sally Talley and her would-be beloved, the Jewish accountant Matt Friedman. The least known, and praised, of the three, Talley & Son (originally written as A Tale Told but later rewritten and renamed) followed.

Mr. Wilson himself was from Missouri, and treated the characters in his plays with the even, reasonable perspective of a Midwesterner. He was born to Ralph Eugene and Violetta Tate Wilson in Lebanon, MO (which is also the hometown of the Talley family). Following the divorce of his parents, he moved with his mother to Springfield. She remarried and when he was 11 and they moved again to Ozark.

After a six-year stay in Chicago, where he attended the University of Chicago and began writing plays, he moved to New York in 1960. His first produced works were mainly experimental one-acts such as Ludlow Fair, Home Free!, and The Madness of Lady Bright. The latter — one of the first major American plays to openly examine modern gay life — bowed at the Caffe Cino in May 1964 and was a hit, enjoying a long run at a venue know for short stays. Soon after, Balm in Gilead, one of Mr. Wilson's most significant early plays, debuted at LaMaMa and played to sold-out houses. Set in a sordid greasy spoon that might have been a 1960s New York descendent of Harry Hope's Saloon in The Iceman Cometh, it sympathetically surveyed the doomed trajectories of a community of largely unsympathetic social misfits and deviants. The play's reputation was solidified in 1984 when it was revived by Circle Rep and Steppenwolf Theatre Company (another ensemble-based company which has long had a relationship with Mr. Wilson's work) in a riveting production directed by John Malkovich and starring Gary Sinise and Laurie Metcalf.

Steppenwolf co-founder Terry Kinney, who appeared in Steppenwolf's 1980 production of Balm in Gilead and the 1984 transfer Off-Broadway, said on March 24, "Lanford was a singular voice in the American theatre — an important artist, a gentle soul and a good friend. We will miss him sorely."

Hot l Baltimore, Mr. Wilson's first major commercial hit, was another repository of outcasts, set in a condemned hotel with a flickering neon sign. A massive Off-Broadway success, it began at Circle Rep and went on to run for more than 1,600 performances, proving that Mr. Wilson was a commercially viable playwright.

Coincidentally, previews of a Steppenwolf revival of the play were scheduled to begin March 24. A moment of silence was to be observed at the curtain, a spokesman said. Steppenwolf artistic director Martha Lavey said, "Wilson is a playwright we feel as one of ours — something in us resonates with the fundamental humanity of his voice."

Lanford Wilson's plays were often ensemble pieces ruled not so much by plot as by the behaviors of rich characters both funny and heartfelt. "I usually don't outline my pieces, and the characters take me where they want to," he once told Playbill.com. As such, they were catnip to actors. Performers such as William Hurt, Judd Hirsch, Swoosie Kurtz and Jeff Daniels rose to stardom on the backs of Mr. Wilson's roles. (Daniels even produced late-career plays by Mr. Wilson, including Book of Days and Rain Dance, in Michigan, at the Purple Rose Theatre.)

John Malkovich, who directed the landmark revival of Balm in Gilead, would return to Mr. Wilson's work in 1987 in Burn This, offering a notoriously flamboyant turn as a magnetic, volcanic New York restaurant owner who takes up with a choreographer, played by Joan Allen. The play, which examined in painfully Chekhovian detail the anguished incompleteness of most modern relationships, was revived Off-Broadway in 2002 — and, as was often the case with Wilson's work, generously reappraised by critics — in a production that was part of a Signature Theatre Company season dedicated to the writer's work.

"Burn This emerges as an exquisitely arranged chamber piece for four self-distancing people who have misplaced their deepest feelings," wrote Ben Brantley in the New York Times. "But it also presents a bracingly clear-eyed portrait of an age of disconnectedness, a state in which American life still seems firmly lodged." (The play is currently in revival by Center Theatre Group at the Mark Taper Forum in Los Angeles.)

James Houghton, founding artistic director of Signature, told Playbill.com on March 24, "Lanford Wilson was a genius. His writing captured the complexity of our everyday lives with enormous wit and a deep humanity. His relentless pursuit of the truth and his fearless courage to speak it puts him among the true greats and will without question enrich the lives of all who encounter his plays for decades to come. To add to all of that: he had a huge heart to match the reach of his work."

His other plays included The Rimers of Eldritch, The Gingham Dog, Lemon Sky, Angels Fall, Serenading Louie, The Mound Builders, among others. Several of these played Broadway in the 1970s and 1980s, and he was nominated for Tony Awards for Angels Fall, Fifth of July and Talley's Folly

He won Drama Desk awards for The Rimers of Eldrich, and was nominated for the award for Fifth of July and Talley's Folly. Wilson's The Hot l Baltimore won the New York Drama Critics' Circle Award, the Outer Critics Circle Award, and an Obie Award.

Mr. Wilson's participation in other media was limited. Hot l Baltimore was turned into a short-lived 1975 sitcom by Norman Lear. Both Lemon Sky and Redwood Curtain were made into television movies.

Mr. Wilson's output slowed in recent years as his naturalistic work fell out of favor. His final Broadway outing, 1993's Redwood Curtain, ran for only a couple months. "There was a feeling that his sentimental portraits of eccentric, dispossessed outsiders belonged to an earlier time, an era still flavored with the individual-worshiping whimsy of the 1960s," the New York Times wrote years later. Furthermore, his longtime artistic home, Circle Rep, hurt by the financial losses of Redwood Curtain, ceased to exist in the early '90s.

Still, new plays did occasionally appear. In 1997, Sympathetic Magic, a play he said took 15 years to write, in which a group of intellectuals gather to debate the forces that govern human existence, debuted at Second Stage. Book of Days, written in 1998, and produced at the Signature in 2002, was a study of small-town hypocrisy. A Sense of Place, or, Virgil Is Still the Frog Boy was produced at the Bay Street Theatre, a company in Sag Harbor, Long Island, near his home. His best known plays, of the '70s and early '80s, are regularly revived.

In 1990, Mr. Wilson told Playbill.com about the productions that put him on the road to becoming a playwright. "What changed my life in freshman class [at Ozark High School] was going to Springfield's Southwest Missouri State College to see a dynamite production of Death of a Salesman. When those walls started vanishing and turning into trees, I was hooked. Almost the same week we saw the touring company of Brigadoon. Again, the floor starts fading away and buildings start to disappear. I almost thought that had to happen in every play. Actually, in Redwood Curtain, I do say 'the floor vanishes, forest and house.' At the end, the forest turns inside out and the house appears. I knew it was possible."

Marshall Mason indicated that a funeral will be in Mr. Wilson's "beloved Sag Harbor, where he will be laid to rest Monday, March 28, only a two weeks before what would have been his 74th birthday."