Way back in pre-Lib 1940, an unknown woman artist had her first solo show in New York at the Galerie St. Etienne. Under a title that might precipitate a riot today -- "What a Farm Wife Painted" -- the brightly colored "naive" paintings of rural American farm life proved an instantaneous success, and a new career was launched for Anne Mary Robertson Moses. She was 80.

Two decades later, "Grandma Moses," as she came to be known, had produced more than 1,200 paintings, many of which had traveled with other American "folk" art all over the country and abroad as ambassadors for the U.S. government. By the time she died at the age of 101, Grandma Moses had become one of the best-known and bestloved American artists of the 20th century.

In a frozen, snowy landscape she would have enjoyed, 43 of Moses' paintings went on view yesterday at the East Building of the National Gallery of Art, this time more innocuously titled "Grandma Moses: Anna Mary Robertson Moses (1860-1961)."

This show spans her artistic career, starting with a "worsted picture" of the sort she made with needle and yarn (and showed among the jams and jellies at county fairs) before she took up painting in her 70s because, as she explained,"... well, to tell the truth, I had neuritis and arthritis so bad that I could do but little work, but had to keep busy to pass the time away." The show ends with a painting made just before her death, appropriately entitled "Rainbow."

"I, Anna Mary Robertson was born back in the green meadows and wild woods on a farm in Washington County, New York," says Moses in one of the delightful excerpts from her writings included in the show. Those "green meadows" were to provide subject matter for some of her most beautiful paintings, including "My Hills of Home." As a child she had made drawings of the landscape which she inventively colored with grape juice and berries, giving lie to the prevailing notion that her creativity had been bottled up until age 70.

At 12, Anna Mary left home to become a "hired girl," cooking and cleaning for various families for 15 years until her marriage to farmer Thomas Salmon Moses. After 18 years as a farm wife in Staunton, Va., Moses returned to her home territory at Eagle Bridge, N.Y., with her husband and the five surviving children of the 10 she bore. It was there that she began to paint after the death of her husband, and there that she remained until her death.

But it is life that Moses' paintings celebrate from the remembrance of holiday festivities (like "Catching the Thanksgiving Turkey") and country fairs, to the humblest farm chores, such as those depicted in "Bringing in the Maple Sugar" and "Making Apple Butter." In two paintings dealing with "Wash Day," a snowy wash floats in the fresh wind (you can almost smell it), the shape of each shirt and towel lovingly laid out and studied, as if the artist were making an abstract painting or a patchwork quilt.

This interest in patterning -- as well as color -- is clear throughout her work, and plays a major role in its formal staying power. Subject matter like "A Checkered House," with its patterned cornfields and apple orchards in the background, obviously fascinated her. In "Quilting Bee," she tips the quilt -- and the nearby tabletop set for a ham dinner -- so that we can share her pleasure in the patterns they form, as well as the joy of a family gathering around a roaring fire.

The prevailing mood in all of these paintings is pleasure and contentment with the simple events of life, and it is communicated in every detail. Even a threatening blizzard or hurricane or thunderstorm fails to disturb tranquility, though hats fly, trees sway and skirts whip around formless bodies as the cows brace matter-of-factly against the wind.

That even the worst weather was taken in stride, in her life, as in her art, was made clear when Grandma Moses came to Washington in 1949 to receive an award "for outstanding accomplishment in art" from the Women's National Press Club. Invited to tea at Blair House with Harry S. Truman, she was amused at his reassurances during a "terrific thunderstorm. 'Don't be afraid, as this is a large building and has many lightning rods on it,'" said the president. "Maybe he thought Grandma would be afraid," said the understanding Moses.

Harry Truman was only one of many residents she captivated. Fellow self-taught painter, Dwight D. Eisenhower so admired her work that, as a gift to him, his Cabinet commissioned Grandma Moses to do a painting of the presidential farm in Gettysburg. It hangs in the Eisenhower Library.

And even Amy Carter turns out to be a fan."July Fourth, 1951," owned by the White House, has been loaned to the exhibition right off the walls of Amy's playroom.

"I thought of it no more than of doing fancy work," Moses once said in appraisal of her paintings. The art museums of the world obviously saw in them considerably more. Among the lenders to this exhibition are the Metropolitan Museum of Art, N.Y.; the Musee National d'Art Moderne, Centre Georges Pompidou,Paris and the Gemaldegalerie of the Kunsthistorisches Museum, Vienna. Mr. and Mrs. ving Berlin, appropriately, have loaned "White Christmas."

"But I will say that I have did remarkable for one of my years and experience," said Grandma Moses.

The show will continue on view at National Gallery East, first pod to the left, through April 1.