A prominent Manhattan socialite is swapping her big-city lifestyle for Southern charm after purchasing a historic downtown estate for $4.8 million.

Patricia Altschul bought the Mikell House, a 9,480-square-foot mansion built in 1851 at Montagu Street and Rutledge Avenue. The stately Greek revival home has columns across the front and is surrounded by formal gardens, a three-room guest house and a carriage house.

Altschul was married to Arthur G. Altschul, a noted Wall Street executive, art collector and philanthropist who died six years ago. She plans to move to Charleston permanently but keep her New York home, said Thomas Bennett, a real estate agent with Carriage Properties who represented the buyer.

The historic estate was built by cotton planter Isaac Jenkins Mikell for his third wife. Between 1936 and 1960, it was used as a county library, and the house later faced demolition because appraisers said the land was worth more than the structure, according to newspaper archives.

Instead, a Philadelphia couple bought the house, renovated it and sold it to the Historic Charleston Foundation. The group sold it for revenue and, since then, the property has had several owners.

Charles Sullivan, also of Carriage Properties, originally listed the house at $5.99 million. The sellers, Ken Lock and Susan Sharpe, sold the home and moved to California to be closer to family.

The sale ranks as one of the priciest transactions for a home in downtown Charleston. The record is held by 21 King St., which was sold in June for $7.2 million to Boston hedge fund operator Jim Pallotta, That home is back on the market for just under $7.9 million.

Bennett said the Mikell House is one of the few landmark houses across the country that attract attention from an elite group of buyers.

"There are some people who just search for great houses," he said. "They love houses, they love architecture, they love beautiful places, and the draw for Charleston is it has incredible houses, yet it's a city that's vibrant."

He added that homes that belong to this special class are always in demand.

Altschul, for example, looked for a historic Charleston home for about two years before buying the Mikell House. Bennett said she plans to make a few minor changes to the house, including reworking the landscape, updating the kitchen and reformatting the interior to make it more like a single-family residence.

Some of the property's previous owners, including Bennett, rented out the house as apartments, so some of the room configurations need to be changed, he said.

Bennett owned the property in the early 1980s. Since then he has helped sell the house five times, but said he regrets not keeping it when he had the chance.

"Out of foolishness and greed, I sold it. I should have kept it," he said. "You don't know how well you have it until you lose it."