The town of Nelson, Pa., sat right in the flood plain. Or what was about to become the flood plain.

"The town was like a corner grocery store and a gas pump or two, a Civil War burial spot and some magnificent houses," Rep. Joe McDade remembers. "And here comes the {Army} Corps {of Engineers} and they say, 'Well, we're sorry, but the water is going to back up and we're going to have to move these people out of here.' "

The people of Nelson didn't much care for this plan. When they found out that most of the available housing was across the state line in New York, the people of Nelson called their congressman.

"Ila Wiley," McDade says, enjoying the musicality of the name. "She was the mayor of the town. Ila. Isn't that wonderful? She's a marvelous lady."

McDade brought the marvelous lady to Washington where, together, they persuaded the House Public Works Committee that Nelson deserved to endure.

So, in July of 1979, the United States Congress moved the tiny town lock, stock and cemetery, to the top of a nearby hill. "The New Nelson," McDade says. "They've got their original buildings and they're thrilled."

The congressman leans back a bit in the chair behind his desk in his third-floor office in the Rayburn Building. He is beaming and he wants you to beam, too. The story has been told in response to a question about the greatest accomplishment in his 25-year congressional career.

Imagine that Mr. Smith came to Washington -- and stayed. That's Joe McDade. He is a short, almost stocky man with a cherubic face, a wave of receding white hair and a soothing voice. Given to "gosh" and "golly," he seems altogether too sunny to be taken seriously by his peers. But the 13-term Republican representative from northeastern Pennsylvania has, with scarcely a whisper, become one of the most popular and most effective members of the House.

"He is one of those guys who is very effective by learning the ropes and being a nice guy," says Rep. Morris Udall (D-Ariz.). "I don't know anybody who doesn't like him."

One of those guys. For every celebrity congressman who sees the House as a chance to campaign for higher office or ideological sainthood, there are a score, like McDade, who go unnoticed by all but their colleagues and constituents. They don't Face the Nation. They never Meet the Press. You won't find them sitting in the Crossfire. As a result they are all but invisible on major national issues.

"I don't get satisfaction or jollies out of being on the network or the evening news or Page 1," says McDade, who initially refused to be interviewed for this story. "I don't ever remember passing out a press release in the press gallery in the 25 years that I've been here."

McDade is a model casework congressman, the kind who sometimes seems to function as little more than an ambassador for his district. His low profile leads people to underestimate him.

"They are important guys on committees," says James Lengle, associate professor of political science at Georgetown University. "Because they are nonideological, they can be swayed. They are the guys who form the consensus."

In describing McDade's tenure, "Politics in America" notes that he spent "years as an inconspicuous Appropriations 'specialist' . . . lobbying for money to help the coal industry . . . Outside the energy field McDade's only consistent specialty has been small business . . . {he} has played no real political role within his party."

Yet his career represents a triumph for humble-pie politics. As older members retire and others pursue more glamorous positions, he remains one of the few minority party members who can make the cantankerous, compromise-oriented subcommittee system work.

Now, after dwelling for years in the dark forest of anonymity, McDade has ventured into the tall grass of obscurity. He is in his third year as the ranking member on the House Appropriations subcommittee on defense, a post he says "draws you inevitably into national affairs."

Americans, the saying goes, hate Congress and love their congressmen. A representative is expected to serve the national interest, but he is also expected to be a procurement officer for his district. Everyone is in favor of fiscal responsibility, but everyone wants his slice of the pie. Joe McDade, the model casework congressman, works at the difficult trick of serving two masters.

And at 55, with one of the safest seats in the country, he will have the levers of power within his grasp for at least another decade.

Consensus and Consistency When the coal was gone there wasn't much left and what was left was ugly. Sections of Scranton stank from the sulfurous fumes that drifted off burning piles of a coal byproduct known as culm. Merchants were evacuating the downtown. The river was gray and inhospitable to fish.

"I hate to even go back into it," Joe McDade says. "When I first came here, we had burning culm dumps, we had mine subsidences all over the place. We had a very high rate of unemployment and we had an awful lot of people who were suffering. Literal economic suffering. And I think that has shaped everything I've tried to do since I got here."

McDade, the city's solicitor, first sought office in 1962 as soon-to-be-governor William Scranton's handpicked congressional successor. His Irish Catholic background played well in Scranton, while his Republican principles appealed to a large rural population. He was elected with relative ease.

In Washington, McDade set about doing what he could to pump life, and federal funds, into his corner of Pennsylvania. He was aided and overshadowed in this endeavor by Dan Flood, the powerful and flamboyant Democrat who represented neighboring Wilkes-Barre. The years of living invisibly had begun.

"Down here {in Harrisburg, the state capital} they still think Dan Flood is my congressman and he's been out of office for six years," says Robert Mellow, a Democratic state senator from Lackawanna County.

McDade's beatitudes then, as now, began with: Blessed are the consensus builders. A moderate Republican in a predominantly Democratic district, he dispensed early with ideology. The conservative Americans for Constitutional Action like about half his votes, while the liberal Americans for Democratic Action have given him about a 40 percent approval rate. His highest marks, roughly 66 percent, come from organized labor, but he scores almost as well with the Chamber of Commerce.

"I'm not the kind of person who cannot see two sides of an issue," he says. "That's what I try to do. Not try to take a side of an issue and say, 'Well, hey, that's it,' and go proselytize it, put out a press release, go make speeches."

A publicity-free style masked his growing influence with colleagues. Until he left the Appropriations subcommittee on the interior subcommittee three years ago, he and subcommittee Chairman Sidney Yates (D-Ill.) were regarded as one of the best legislative teams in recent House history. "I don't think we ever lost a floor amendment that we worked together on," McDade says.

"He has the ability to put together packages that are acceptable to everyman," says Rep. Don Young (R-Alaska).

But McDade has not shunned confrontations with the powerful. Jordan Clark, a former chief aide, remembers the early years of the Reagan administration as particularly combative. "{Former budget director David} Stockman would sit on the couch and tell him why he was going to get rid of Economic Development and the Appalachian Regional Commission and the Small Business Administration and Joe would get exercised and frankly tell him he wasn't going to do it," Clark says.

The programs were saved, but their funding was slashed. Supporters in Pennsylvania's 10th congressional district count the budget battle as one of McDade's victories. They also credit him with securing federal funds to clean up the environment in the aftermath of the collapse of the coal industry, luring developers into Scranton's downtown and coaxing a variety of businesses to locate in the district.

McDade's effectiveness, his relationship with William Scranton and his knack for winning easy reelection made him an attractive candidate for higher office. The governorship bored him, but the Senate didn't. "I had my shots," he says. But he never made the run.

Some friends say he didn't want to sacrifice his seniority in the House. Others say he didn't want to give up a quiet family life for an arduous statewide campaign. Critics suggest he lacked ambition.

"The key thing was the money," he says somewhat wistfully. "I can remember sitting in a room when they were trying to get Governor Scranton to run for governor and I know it was always in his mind that some of the pols were going to try to roll him because he was a wealthy guy. And there was a guy named Tom McCabe who was a Republican National Committee man.

"He was the chairman of the board of Scott Paper. Wonderful, beautiful man and his antenna could sense that issue with Governor Scranton and so he said to him, 'Look, Bill, you are a substantial citizen, we would expect you and your wife to make a substantial contribution, but we're not going to ask you to finance the campaign. I'll raise the money.'

"Now that was a beautiful thing for him to do. I didn't have a similar experience, so that was the end of my Senate aspirations."

He says it didn't sting so much. Or that he didn't remember it stinging.

The World & the District In the House of Representatives, good things come to those who wait. What came to McDade in 1985 was the role of ranking Republican on the Appropriations defense subcommittee.

"I had to manage the bill on nonlethal aid {to the contras}," he says. "I had to manage the bill on the MX missile. You are inevitably thrust into world-shaking issues. I don't have as much time to be on the phone to the agencies arguing for a grant for my constituents. There's no question about that."

But with increased responsibility came increased influence. As Jordan Clark points out, "There are few districts in the country that don't have some kind of defense activity."

Now instead of two masters, McDade serves three: a Congress that wants to trim the defense budget, an administration that doesn't and a district that wants a piece of the military-industrial complex to call its own.

"There are those who feel explicitly that I am a mail carrier, or a courier, if you will, for whatever they {the Reagan administration} want done," he says. "I'm not, nor will I be and I make that clear to them. Gosh, last year there was no question that I had a lot of people at the Pentagon angry over the defense appropriations bill."

Making enemies doesn't worry McDade. Making decisions on a project as mysteriously technical as the Strategic Defense Initiative does.

"You can have the scientific community come in one day and say, 'Yes, the United States can do this and they can do it in a cost-effective way.' And the following day you can have eminent scientists come in who disagree," he says.

"And increasingly in my experience around here, that's the world today in Washington, where you get the experts on both sides and you find disagreement among people where you think there might be commonality of opinion. Increasingly there are judgmental calls on complex scientific questions that certainly very few members, if any, can deal with themselves."

After a few weeks lost in space, there is a certain appeal to something as basic as a little legislative muscle-flexing on behalf of the folks at home.

Last October -- over the objections of the Reagan administration, the National Park Service and most experts in the field -- McDade secured a $25 million authorization to build a railroad museum out of a struggling theme park in Scranton's sagging downtown.

His maneuvering meant the site did not have to undergo a lengthy Park Service study that usually precedes any designation. As a result Steamtown, a railroad memorabilia collection of dubious worth, will soon be counted as a National Historical Site, a category that includes Lincoln's birthplace and Martin Luther King Jr.'s grave.

President Reagan proposed that the initial $7.9 million scheduled to be appropriated in 1988 be withheld until the "historical character" is established, but Congress took no action on the proposal.

"On the basis of place in American history, no competent historian in my opinion would {choose} the Scranton and the Steamtown collection, as, in effect, the national railroad museum," wrote John C. White, transportation curator and senior historian at the Smithsonian Institution in a letter to Interior Secretary Donald Hodel.

Said John Roberts, who runs the prestigious St. Louis Museum of Transport: "Of all the collections they could have picked out, this was the weakest."

In many ways, the Steamtown vote was the crowning achievement of McDade's career to date. As Don Young puts it: "He was able to come up to me and say 'Don, this is very important to me and important to my district and what can you do?' That couldn't have happened if he hadn't developed that relationship over the years."

Park Service officials estimate privately that Steamtown will cost $70 million to rehabilitate and $5 million a year to operate.

"That was a tough push," McDade says. "Not everybody in the world was in favor of us having Steamtown in Scranton, Pennsylvania."

The people of northeastern Pennsylvania know this and they are grateful. They have bestowed on their congressman every accolade they know. There is a McDade Park and there is a McDade Homes, a middle-income housing development. Every two years there are McDade Opponents, lambs who go gently to the electoral sacrifice after attracting about 30 percent of the vote. McDade's seat is so safe that he doesn't get home much anymore. He and his wife Mary have raised four children and live near Arlington.

It's hard to find anyone who doesn't have something nice to say about Joe McDade, except maybe that he hasn't cut quite the figure that he could have.

"He has not, for sure, exercised the kind of leadership a guy could exercise with that kind of experience in Congress," says James Haggerty, secretary of the Commonwealth of Pennsylvania. Haggerty nearly unseated McDade in 1964, the congressman's only closer race.

"Forget national exposure," says Robert Mellow, who is occasionally mentioned as a prospective opponent. "He doesn't have state exposure. I think it would be healthy for our area if he exerted the kind of national influence he could have."

McDade has heard this before, from critics and from students of Congress. "I remember one time picking up a journal of politics and I was reading about myself," he says. "I was kind of upset that a lot of the things that I thought were national issues were not getting any attention by the people who were writing the report . . . as they critiqued 25 years of my life."

This hits him where he lives, this idea that he's been effective, but not on anything that matters much. It is not an opinion his colleagues share.

"There is a misconception," says Rep. Jack Murtha (D-Pa.). "With his position on Appropriations, unless he were to run for the executive branch, it would be difficult to have much more influence."

The portrait of Joe McDade is a variation on the portrait of Dorian Gray. The fruits of his success are visible on the landscape of the district, not in the perception of the man. By embracing his limitations he has, on occasion, transcended them.

"I . . . spend a huge amount of my time on kind of trying to do what I can to preach about the area," he says. "Preach about its people, preach about what it has to offer. That for me is the full banquet, the full platter.