A few weeks ago, with winter in mind, I posted this picture of tractors on the National Mall during a snowstorm for my weekly “Sneak Peek” feature, highlighting interesting images in our photo archives. My initial research into the image made me realize there was an interesting story these tractors had to tell.

In February of 1979 farmers from the American Agriculture Movement (AAM) organized a tractor rally in Washington, DC in the hopes of driving change in agricultural policy. Thousands of farmers made the trip to Washington in their tractors, traveling across the US at fifteen miles per hour and covering no more than one hundred miles per day. Collecting along highways, they traveled in convoy and descended on the nation’s capitol on February 5, 1979.

The protesting farmers occupied the National Mall for weeks, demanding more pay for crops and lobbying for an increased role in agricultural policy decisions. An unsympathetic Washington billed the farmers as a nuisance that was costing taxpayers an estimated $1 million in tractor damage to the National Mall.

Tides turned on President's Day weekend when a blizzard hit, covering the city in two feet of snow. The farmers, in possession of some of the only vehicles able to move, rose to the occasion and helped dig out DC. They plowed out hundreds of cars and aided stranded citizens. They transported doctors and nurses to hospitals, where the wives of AAM farmers helped cook and clean because regular staff was unable to get to work. Twenty-two inches and a whole lot of goodwill turned these agitators into heroes.

During their weeks on the National Mall, the farmers frequented the Smithsonian museums, taking refuge from the cold winter days and eating lunches in the cafeterias. In 1986, the American Agriculture Movement donated one of the tractors from the 1979 tractorcade to the National Museum of American History. Since those times, AAM plays a key role in agricultural policymaking in Washington, DC.

In this case, a little bit of digging revealed a rich story about why this “tractorcade” was an important part of American history.

Late in July, LENS, a New York Times blog that focuses on images and issues photographic, posted an interesting story by James Estrin. Magnum Photos, the legendary co-operative photo agency founded after World War II by photographers including Robert Capa and Henri Cartier Bresson, announced that to boost the visibility (and paid use) of the hundreds of thousands of images it has already placed online, it would look for 50 volunteer taggers to help key word its online images. Teaming up with Tagasauris, a company that specializes in tagging archival pictures, the goal was to enlist photo-enthusiasts, whose tagging suggestions would then be reviewed by three-to-five participants before they were posted.

What might be likened to an unpaid digital-archive-internship, promises to give participants opportunities to study older photos that were seldom seen, as well as new images by Magnum photographers as they enter the archive. For those interested in the work of photojournalists as diverse as Eve Arnold or Susan Meiselas, Elliott Erwitt or Tim Hetherington, and who want to support Magnum’s mission at time when  professional photojournalism is being challenged both by the shrinking number of paying media venues and the rise of citizen journalism  it seemed like a win-win opportunity.

Early in August, another article, this one in Britain’s Independent reported more on the story, and from a slightly different angle. Crowd-sourcing, as Alice-Azania Jarvis wrote, is not special, in itself. But what Magnum has done is introduce incentives like “leader board-style status-enhancers to virtual rewards” to make the process fun, competitive, and popular. Todd Carter, a Tagasaurus executive, suspects that if the tagging process were truly “gamified,” millions of people might want to sign up. (The gaming-tagging concept, as Effie Kapsalis of Smithsonian Institution Archives just pointed out to me, was first tested out by Google in 2006.) One potential consequence of that would be that many gamers might lack the historical and/or photographic expertise to comment on much beyond the more obvious subject matter the images depict. As it turns out, less than two weeks after the Times piece ran, thousands of people have already contacted Magnum, which—with its 295,000 Twitter followers and 135,000 Facebook fans—plans to stick to its goal of finding 50 knowledgeable volunteers, and now looks like it will have plenty of  potential taggers to choose from.

Magnum is not alone in its outreach efforts to sign up the public to help in archival work. The Smithsonian currently has a public collection tagging initiative in the works.