DURING THE NEW DEAL era, government agencies hired photographers to promote their programs. Dorothea Lange, with her famous dust-bowl images of migrant farmers and laborers, was one of the best.

Her employer, the Farm Security Administration, offered tenant loans, established cooperative farms and otherwise made efforts to ease the effects of the Depression on the rural poor. But its photography project told a bitter tale that paralleled Steinbeck's "The Grapes of Wrath." The images captured by Lange, Walker Evans and Russell Lee are unforgettable.

By contrast the Department of Agriculture photos concentrated on the more prosperous farmers -- the success stories. Perhaps that's why they are the unfamiliar scenes in "Official Images: New Deal Photography," at the American History Museum -- an exhibit of photos from USDA, FSA and three other agencies (the Civilian Conservation Corps, the National Youth Administration and the Works Progress Administration).

The Agriculture Department's photographic message was that all was well if you stuck with them. Which is just not as interesting historically, as well as being entirely suspect. George Ackerman's photo of an apple-cheeked 4-H girl giving a canning demonstration is technically very good. But it can't compare to Lange's photo of a man showing off the new pair of shoes he has just fashioned from an old tire.

John Vachon photographed a man in a city dump for the FSA, and here is the apologetic caption: "Foraging for food at the city dump. Produce houses dump apples, grapefruit, oranges, etc. which are not quite bad. Dubuque, Iowa, April 1940." But in the USDA photos, farmers receive benefit checks and sell apples at bountiful roadside stands.

OFFICIAL IMAGES: NEW DEAL PHOTOGRAPHY -- Through January 1988, at the Museum of American History, first floor.