''Welcome to Rockwell Land,'' writes Deborah Solomon in the introduction to this spirited and authoritative biography of the painter who provided 20th-century America with a defining image of itself. As the star illustrator of The Saturday Evening Post for nearly half a century, Norman Rockwell mingled fact and fiction in paintings that reflected the we-the-people, communitarian ideals of American democracy. Freckled Boy Scouts and their mutts, sprightly grandmothers, a young man standing up to speak at a town hall meeting, a little black girl named Ruby Bridges walking into an all-white school - here was an America whose citizens seemed to believe in equality and gladness for all.

Who was this man who served as our unofficial ''artist in chief'' and bolstered our country's national identity? Behind the folksy, pipe-smoking facade lay a surprisingly complex figure - a lonely painter who suffered from depression and was consumed by a sense of inadequacy. He wound up in treatment with the celebrated psychoanalyst Erik Erikson. In fact, Rockwell moved to Stockbridge, Massachusetts, so that he and his wife could be near Austen Riggs, a leading psychiatric hospital.

''What's interesting is how Rockwell's personal desire for inclusion and normalcy spoke to the national desire for inclusion and normalcy,'' writes Solomon. ''His work mirrors his own temperament - his sense of humor, his fear of depths - and struck Americans as a truer version of themselves than the sallow, solemn, hard-bitten Puritans they knew from 18th-century portraits.''