Some large giving and even larger thanks have marked the nation's preparation for Thanksgiving.

Some potato growers from Aroostock County, Maine, rolled into Washington the other morning with about 1,000 50-pound sacks of round whites. An 18-wheel rig, dispatched by Harrison Farms, parked near the National Shrine, the largest Catholic church in America, where vans from community food banks, soup kitchens and feeding programs were ready for the potatoes.

By one reckoning, the Maine shipment brought the 100 millionth pound of donated potatoes to hungry or poor people since 1983. That year, two rural Virginia United Methodist ministers, both Vietnam veterans, co-founded the Potato Project. With a pair of immense numbers in mind -- the 20 million Americans who endure hunger each month and the millions of tons of surplus or odd-shaped potatoes wasted annually -- the two ministers moved beyond quoting Scripture on the obligation to feed the poor and assumed responsibility.

Thus radicalized, they became locaters of farmers in the 24 potato-producing states, hunger organizations in all parts of the country and financial supporters everywhere. Filled trucks have been rolling since. Last year the Potato Project, headquartered in Big Island, Va., delivered 15 million pounds of potatoes.

When a crowd of 150 community organizers and their friends came out to celebrate the delivery of the 100 millionth pound, a festive moment, workers from one of the soup kitchens served up what Washington loves most -- a power lunch. It was a bowl of powerful vegetable soup, with chunks of potatoes packed with fresh nutritional zest.

Few vegetables -- and assuredly no meats -- are as health-giving as the potato. It is cholesterol- and fat-free, low in calories and price, high in fiber if unskinned and has six times more potassium than rice or pasta. Potatoes are the reason that soup-kitchen soup is often healthier and more filling than the watery over-seasoned stews served in high-price restaurants.

Ray Harris, the general manager of Harrison Farms, stood near his tractor-trailer as it was being unloaded and spoke about restaurants and stores. It's because they want perfectly shaped wonders -- Grade A specimens -- that farmers are left with tons of nicked or misshapen potatoes. "We used to throw them away," Harris said.

The 1980s saw a surge in food-gleaning programs, ranging from Second Harvest, a national group, to local caterers, bakeries, restaurants, clubs and hotels. Second Harvest has 88 food banks and 112 affiliates in 46 states, with a record 411 million pounds of food distributed that would otherwise have been lost.

Few in Congress have done more than Rep. Tony Hall (D-Ohio), who became chairman of the House Select Committee on Hunger after the 1989 death of Rep. Mickey Leland (D-Tex.). Hall, who spoke at the 100-millionth-pound celebration, said afterward: "The wonderful thing is, you don't need an act of Congress to glean food. Anyone can do it. A friend of mine in my district has a farm with a field of corn. A few summers back, I went into the field with him, and he picked some ears. 'I can't sell these,' he said. A few kernels were missing from each. 'They're imperfect,' he said. 'Americans will buy and eat only perfect-looking food.'

"I found out later that we throw away 60 million tons of so-called imperfect food a year. On that farm in my district, some church people got together, and we've been picking the unsellable corn ever since. Last year we saved four times more food than the year before."

It's needed. The National Conference of Mayors reports that requests for emergency-food assistance increased 19 percent in 27 surveyed cities in 1989. Three out of five people asking for help were children or their parents. An average of 17 percent of the requests went unmet, because the shelves were empty. People were turned away in three-fourths of the cities.

Up against that, 100 million pounds of potatoes are still small potatoes. The heroic work of the Virginia ministers -- they now run the Potato Project full-time, including fund-raising for it -- is a modest example both of what can be done and should be done.

The presence of hungry Americans refutes daily the patriotic blather that we are a great nation. Where's the greatness in letting the hungry stay hungry, while an estimated 20 percent of our grown or produced food is thrown out or left to rot?

Thanksgiving, the feast of plenitude, should be a moment of gratitude for the large numbers of citizens -- including potato farmers and their truckers -- who answer that question by taking action.