The 1838 Colonial Revival mansion known as Oakdale was home to former Maryland governor Edwin Warfield. (HomeVisit)

Nearly 40 years ago, when Theodore F. Mariani first saw Oakdale, what struck the architect was not the Colonial Revival details of the historic home, but the mature, majestic trees on the property. Besides native species of black walnut and oak, specimen trees — sweet gum, weeping beech, horse chestnut and great pine — had been planted by a former owner. The Maryland Big Tree Society has identified 10 champion trees on the property.

“I said to myself, ‘I can design a great house, but I can’t grow a tree,’ ” said Mariani, who was the lead architect for the Washington Convention Center and for the historic preservation of Pennsylvania Avenue and Federal Triangle. “I was so enthralled by the trees. It’s a marvelous natural setting.”

The house isn’t bad, either. Built by Albert Warfield in 1838 as a large brick Federal-style house, it was enlarged in 1879 and 1891. Warfield’s son Edwin, who was born in the house in 1848, added the Colonial Revival details in 1898.

The Warfields are one of the prominent old families of Maryland. Richard Warfield arrived from England in the mid-1600s and became a wealthy planter and an officer in the militia. His descendants included two Maryland governors, Charles Carnan Ridgely and Edwin Warfield, and an infamous duchess, Wallis Warfield Simpson, for whom King Edward VIII abdicated the throne of England.

Edwin Warfield was elected to the state Senate in 1881 and was made president of the Senate in 1886. He resigned to accept an appointment by President Grover Cleveland as surveyor of the port of Baltimore. Warfield was more than a politician. He also bought and edited the Ellicott City Times and the Maryland Law Record (later called the Daily Record). He founded the Patapsco National Bank of Ellicott City and the Fidelity and Deposit Company of Maryland. He was president of the Sons of the American Revolution and of the Maryland Historical Society.

Edwin Warfield, a Democrat, served as Maryland governor from 1904 to 1908. He declined to run for a second term. The New York Times called him “the most versatile Executive who has presided at Annapolis” when he was elected.

Warfield used the house mainly as a summer residence and for entertaining. Wallis Warfield Simpson was said to have attended parties at the home, as was Mark Twain.

“I’ve heard this story,” Mariani said. “The governor was entertaining Mark Twain, and Mark Twain made the comment, ‘Who had this land before you acquired it?’ And [Warfield] said, ‘Before the Warfields, only God and the Indians.’ ”

Oakdale remained in the Warfield family until 1974. It had one other owner before Mariani bought it in 1981. Previous inhabitants had altered the interior, but Mariani restored the house to its original state as best he could.

“We’ve tried to maintain as much as possible,” Mariani said.

View of Oakdale estate (HomeVisit/HomeVisit)

Oakdale remains a working farm with 70 acres of crops. Mariani maintained an equestrian facility for a time, with about 17 horses. Within the past five years, he planted grapevines, with the intention of producing wine.

“The other thing nice about this setting, I put my farm in what is called ag preservation, which means it will never be developed for residential development,” he said. “It will stay as a farm. A number of my neighbors have done the same.”

Asked what he loves best about Oakdale, Mariani said the “serenity.”

“We’ve enjoyed being out here,” he said. “It’s quiet. You can sit on the front porch and enjoy the views.”

Oakdale, which is on the National Register of Historic Places, is listed at $10.3 million. The property includes a 12-bedroom, six-bathroom, 9,500-square-foot main house, a 120-foot colonnade that connects to an 8,870-square-foot entertaining hall, a carriage house, a gardener’s cottage, a brick smokehouse, a gazebo near a spring-fed pond, a three-level stable, a barn, a silo and an equipment shed.