Bloomingdale's rediscovered America last night. At a benefit opening of its "America the Beautiful" celebration, the store, whose past promotions have emphasized the products of China, Ireland, India, Israel and the Philippines, hung out the Stars and Stripes and welcomed guests to its White Flint store with a rousing march from the Bethesda-Chevy Chase Marching Band.

More than 600 guests, who had marked their tickets as contributions to either the Textile Museum or the Washington Project for the Arts, wandered down the aisles sampling bits of Americana brought in from the 50 states. They sampled kosher hot dogs from a pushcart, watched the White Eagle Dancers and and admired the costume Judy Garland wore in "The Wizard of Oz," complete down to the ruby slippers.

"It seemed, even when we started this project in mid-1981, there was a great interest in intensifying business with American manufacturers," said Marvin Traub, Bloomingdale's chairman. "We're also very much aware of an increasing interest in American crafts."

Craftsmen, including a weaver, a potter, a basketmaker and a quilter, demonstrated their skills last night. Guests also got a glimpse of new products designed in conjunction with the Museum of American Folk Art. Bloomingdale's interior design staff interpreted American design trends adapted to Rehoboth Beach, Middleburg, Va. and the Watergate.

For the occasion, Bloomingdale's revived the original Cracker Jack box, the Hershey's tin and offered Goo Goo Clusters from the Grand Ole Opry.

Daniel Boorstin, librarian of Congress, who was given a creativity award by Traub, was all in favor of the promotional focus on America. "We need it more than other countries do," he said. When George Stevens, American Film Institute director, accepted his award, he said he had started the day with three wishes -- that the Orioles and the Dodgers would win, and that he'd get an award from Bloomingdale's. He then held up the card from his gift, and deadpanned: "For the next 12 months, you and all of your friends and all of your family will be able to shop in Bloomingdale's for free."