SHEPHERDSTOWN, W. Va. — Six miles south of Boonsboro, Maryland, State Highway 34 passes through the town of Sharpsburg, and three miles farther south crosses the Potomac River into West Virginia, where it becomes Highway 480 and enters Shepherdstown, snuggled against the river’s southern bank.

A few hundred yards east of the highway bridge, the Potomac is shallow. There, at a place called Boteler’s Ford, Gen. Robert E. Lee’s Confederate army crossed the river in its September 1862 retreat after fighting off Gen. George McClellan’s Union army at Sharpsburg in a bloody stalemate known as the Battle of Antietam.

Lee fought another small battle at Shepherdstown, a rear-guard action that cost him five cannon. By inflicting a few hundred casualties on his Union foes, however, Lee caused the cautious McClellan to halt the pursuit and allow the Confederates to retreat unmolested.

The history of Shepherdstown was probably unknown to the aide that chose the site where Sen. Hillary Clinton kicked off her campaign for next week’s West Virginia Democratic presidential primary, following Tuesday’s split decision in North Carolina and Indiana.

“We were very excited about our come-from-behind victory in Indiana,” Clinton told a noontime crowd that gathered to see her and daughter Chelsea at Shepherd University yesterday, adding that “we came from about eight or so points behind to win.”

HER SUPPORTERS MAY have been encouraged by Hillary’s portrayal of her Indiana win as a “come-from-behind victory,” but her slender margin there — less than 19,000 votes, about 1.5 percent of the votes cast — was a disappointment nearly as daunting as Sen. Barack Obama’s crushing 14-point win in North Carolina.

True enough, polls in Indiana three weeks ago had shown Obama leading by 5 points (rather than the “eight or so” Clinton claimed yesterday), but that was before her big April 22 win in Pennsylvania raised hopes of a Hillary comeback. The day before Tuesday’s primary, Survey USA released a poll showing her ahead by 12 points in Indiana.

Hillary’s supporters cheered and chanted her name at the West Virginia event, but reporters pounced at a post-rally press conference, suggesting it might be time for her to strike the tent. Does her vow to keep fighting, asked one network TV reporter, mean that Clinton will continue her campaign all the way until the vote on the convention floor in Denver?

“I’m staying in this race until there’s a nominee, and I obviously am going to work as hard as I can to become that nominee,” she answered. “So we will continue to contest these elections and move forward.”

The reporter fired back with a follow-up question: “But what do you say to those Democrats who fear that you’re putting the Democratic Party’s chances at risk by…continuing to stay in?”

SUCH QUESTIONS CAUSED Rush Limbaugh (who claimed that his “Operation Chaos” delivered Hillary’s margin of victory in Indiana) to wonder why the “Drive-By Media” were so concerned with the Democratic Party’s chances in November.

“All of these media types are demanding that Hillary drop out of the race now . . . and the Drive-Bys are saying, ‘Get out of the race to save the party.’ Now, what’s the party got to do with the media? I ask rhetorically, of course,” Limbaugh told his listeners after watching TV coverage of the Shepherdstown press conference.

Despite disappointments and pressure from a press corps that eagerly reported Democrats saying yesterday that her campaign is now doomed, Hillary continued to suggest ways she could yet win.

She insisted that the disallowed delegations from Michigan and Florida be seated as a matter of “fundamental fairness … [to] two important states that Democrats have to try to win in November.”

Such a move would increase the convention total needed to win the nomination — pushing back the goal posts for Obama, who is currently calculated to be within 200 delegates of locking up the nomination. Yet even Clinton’s own strategists were reported yesterday as saying her chances are now almost a mathematical impossibility.

The primary schedule, however, appears to give the Clinton campaign two weeks of breathing room. Polls show Hillary heavily favored to win in West Virginia on Tuesday and in Kentucky on May 20, the same day as the Oregon primary in which Obama is favored.

A FEW MINUTES before Hillary’s Shepherdstown speech, Clinton spokesman Mo Elleithee dismissed doomsayers in the media.

“The pundits have counted us out since Iowa,” he said. “The funny thing about elections is, the voters get to make up their own minds.”

Barring a decisive tsunami of superdelegate support to Obama, the campaign will continue. As Clinton vowed to fight on in West Virginia, she probably never pondered the historical significance of the site.

Lee’s army suffered thousands of casualties at Antietam, and if McClellan’s numerically superior force had pursued the retreating Southerners, a decisive Union victory might have brought the war to a swift conclusion. After Shepherdstown, however, McClellan was content to let the Confederates continue their retreat, to fight again another day.

The South still lost the war, but it lasted nearly three more years.