This is the Mansion House during the Civil War. (Library of Congress)

Alexandria officials are counting on a new PBS drama, set in the city in the 1860s, to draw a fresh crop of visitors to this D.C. suburb, where tourism is its lifeblood.

“To say we’re excited about this is an understatement,” Patricia Washington, president and chief executive of Visit Alexandria, the city’s tourism agency, told several hundred filmgoers who came to the AMC Hoffman Center theater Thursday night to watch the first episode of “Mercy Street.”

“Alexandria is integral to this story,” Washington said. “We are front and center, not just the backdrop.”

With a $50,000 state marketing grant from Virginia, the tourism agency has launched a Web site tailored to the show (
) that it hopes will appeal to a national audience. Officials are working with local museums to set up show-related visitor experiences.

Washington is predicting a 10 percent increase in visitors, or about 330,000 additional visits, which could mean tens of millions of dollars in restaurant meals, shopping and hotel stays.

The Mansion House in present-day Alexandria. (CM for Visit Alexandria)

“Beyond the Battlefield,” a guided walking tour keyed to the PBS series, will take place at 10 a.m. Saturday starting at the Lyceum, the local history museum. Performances, teas, tours and exhibits pegged to the show are set to start in 2016.

“Mercy Street,” which is scheduled to air after the hit show “Downton Abbey” starting Jan. 17, follows the experiences of two volunteer nurses on opposite sides of the Civil War who meet in the occupied Southern town of Alexandria. One woman’s family owned a once-luxury hotel converted into a Union Army hospital; the other, a widowed Boston abolitionist, is looking for a useful life as a nurse.

The season’s six episodes, based on real events, tell the stories of nurses and doctors, slaves and freedmen, wounded soldiers, prostitutes and spies.

Much of the material came from documentary sources such as memoirs and diaries, and from local and national archives. The sometimes grisly medical scenes, as well as the costumes, are authentic to the period.

“I call it ‘M*A*S*H’ meets ‘Gone with the Wind,’ ” said the show’s executive producer, Lisa Wolfinger, who began researching the story four years ago.

Alexandria, founded in 1749 and located several miles from Mount Vernon, is best known for its role in America’s colonial history.

But “the 19th century has always been a big part of our history” as well, said Washington, of Visit Alexandria.

“Mercy Street” was actually filmed in the Richmond area, because filming in Old Town would have required shutting down both streets for weeks, producers said.

But the re-creation of places such as the Carlyle House and other local Civil War hospitals, cemeteries and apothecaries was so exact that the actors — who visited Alexandria only this week — said they were stunned by the resemblance.

To be historically accurate, the producers (who, in addition to Wolfinger, include Ridley Scott of “Alien,” “Thelma and Louise” and “Black Hawk Down”; David W. Zucker of “The Good Wife”; and David Zabel, showrunner for “ER”) relied on historian James McPherson, Civil War medical historian Stanley Burns, local African American historian Audrey Davis and many others.

Virginia provided $2.6 million in rebates to the production, said state film office director Andy Edmunds, based on the $20 million that the production spent this year. Students from some of the 32 Virginia colleges that have film or new media production classes were employed in some way, he said.

“We are not a state that will give a $20 million tax credit,” Edmunds said, but “we want to target series and independent films” for the promotional value and the economic benefit.