by Fred Hobson, Random House, 650 pages, $35.00 . CODE: RAN -12

H. L. Mencken planted several literary time bombs that have brought him back into the public eye in staggered bursts ever since his death. By his instructions, sizable portions of the writer and editor’s private papers were released to the public in 1971, 1981, and 1991, each time sabotaging the works of his earlier biographers. With no more stashes due to emerge, the literary historian Fred Hobson has published an excellent, reasonable account of Mencken’s life, the first to draw on the full mother lode of diaries, letters, notes, and additions.

Mencken was seventeen when, days after his father’s death, he entered the offices of the Baltimore Morning Herald and volunteered for work. He became its star reporter in nineteen months. Hobson argues shrewdly that this was not the end of the father’s influence: He lived on in the strange and often opposed prejudices of his famous son.

By the 1920s Mencken had achieved something unique in America: A critic, not a novelist, was the country’s most argued-about and famous writer. He attacked New England Puritans, the culturally barren South, Methodists, Rotarians, all manner of reformers. He reveled in the foolishness he saw everywhere: “I figure … that my private share of the expense of maintaining the Hon. Mr. Harding in the White House this year will work out to less than 80 cents. Try to think of better sport for the money.” And although he was a collector and user of every unsavory racial epithet, he also advanced the careers of African-American writers from James Weldon Johnson to Walter F. White, worked and associated mostly with Jews despite all his ugly private terms for them, and became the fighting inspiration for the young black novelist Richard Wright.

A stroke stopped his relentless outpouring in 1948. He died eight long years later. This is not the book Mencken would have written (and rewritten), but it is the big, uncringing book he deserved. Hobson concludes with a chapter on Mencken’s lively and notorious posthumous career.