Civil War generals spent four bloody years crisscrossing the fields and mountains that make up what is now Virginia's 7th District, and this year's congressional candidates are doing their best to live up to that heritage.

The campaign organizations of Republican Rep. D. French Slaughter Jr. and his Democratic challenger, David M. Smith -- son of Del. Alson H. Smith (D-Winchester), an extraordinary fund-raiser who once acquired $1 million in one night for Virginia Sen. Charles S. Robb -- are busy trading accusations about alleged late tax payments, shady political contributions and being out of step with voters.

The expenditure of all this ammunition has come as a surprise to this largely rural district, the most Republican of Virginia's 10 districts. The 7th spreads from the West Virginia border across the Shenandoah Valley and the Piedmont to the outer suburbs of both Richmond and Washington, including Manassas, part of Prince William and part of Stafford County. The 7th's 23 cities and counties include Winchester, Charlottesville and Fredericksburg.

Republicans have carried the 7th in 13 of the last 15 presidential, senatorial and gubernatorial elections. However, suburban sprawl creeping outward from Washington and Richmond has brought hordes of new people, and the Smith campaign feels it can attract many of them. The number of registered voters rose 11 percent, to 275,070, between 1984 and July of this year.

Slaughter, 66, has not had an opponent since he handily won an open seat in 1984, but he has raised $384,000 so far to defend his holdings, according to his campaign manager, Tony Likins.

Slaughter's emphasis on constituent service, a strong defense and cutting government spending has gone over well with the Piedmont's farmers, and Slaughter works from a strong base he built representing the Culpeper area in the Virginia General Assembly from 1958 to 1978. There, he supported segregated schools and the poll tax.

He was largely absent from the 1988 furor over plans to build a mall next to the Manassas National Battlefield Park, though the property in question is in his district. Sen. John W. Warner and 10th District Rep. Frank R. Wolf, also Republicans, were much more active in resisting the development, and Slaughter eventually sided with them and the victorious preservationists. He has been dubbed one of the "most obscure" congressmen by the Capitol Hill weekly, Roll Call.

Smith, a 34-year-old minister who heads a solar energy firm, has turned the campaign into an electronic war, faxing new criticisms to media outlets every couple of days. Smith, whose father is his campaign treasurer, said he has raised more than $250,000.

First, Smith attacked Slaughter's acceptance of contributions from political action committees formed by companies that are wholly or partly owned by foreigners. Then he criticized Slaughter's vote against an amendment, which ultimately passed, to the savings and loan bailout bill that imposed civil penalties of up to $1 million a day.

Slaughter's spokesmen replied that such PACs are legal and that Slaughter believed the S&L penalties were unconstitutional, and noted that he voted for the bailout package, including the penalties.

When the Slaughter camp, relying on polls they say show that 90 percent of voters know the incumbent and only 10 percent know Smith, turned down Smith's request for a debate, Smith began conducting a dialogue with a tape recording of a rambling radio interview Slaughter once did.

Smith plays the tape, then takes issue with Slaughter's positions on the S&L cleanup and on abortion. Smith supports abortion rights; Slaughter opposes abortion except in cases of rape or incest or when pregnancy endangers the mother's health.

The Slaughter campaign recently counterattacked with a "truth squad" of 13 Republican state legislators who plan to stump for Slaughter and expose what they say are distortions of the incumbent's record.

Smith is a United Methodist minister serving two Winchester area churches. Republicans have tried to label him as a young, inexperienced liberal with little going for him except a powerful father.

"I can't see the Republicans of the 7th District going for a novice," said Del. Harry J. Parrish (R-Manassas). "Most of the people contributing to the campaign will be giving to the father rather than the son."

Slaughter press secretary John Goolrick sped into Fredericksburg last week just in time to hand Smith's old property tax records to reporters leaving a Smith news conference. The records showed Smith had failed to pay about half the real estate taxes he owed for a three-year period on a Winchester town house. He paid the late tax bill, $621, in July.

"Congressman Slaughter is against imposing any new taxes on citizens, but unlike his opponent, pays those he owes," Likins said.

Several days later, the Winchester Star revealed that Slaughter had incurred penalties from Culpeper County for paying more than $1,300 in real state and personal property taxes one month late.

"Hopefully we can now return to an intelligent discussion of the issues," Smith said.

Smith has emphasized his support for abortion rights and a balanced budget amendment, and his involvement with environmental issues through his Crystalite Solar Marketing Group. The League of Conservation voters gave Slaughter a rating of 10 out of a possible 100 in 1989.

Despite all the activity, many political analysts said they believe Smith is running to increase his name recognition for a future election.

"You have to have a scandal or some issue in which {the incumbent} has alienated a significant part of the district," said Lewis P. Fickett, a professor of political science at Mary Washington College who once ran for the seat. "I don't see any issues."