[4] The estate significantly influenced the development of thoroughbred horse racing in the new world,[5] having one of only two stables to raise two Triple Crown champions.

Mary had previously inherited Middle Plantation in Davidsonville, Maryland when her first husband, Mareen Duvall died in 1699.

As a result, in 1721, a new deed was issued to a much larger 1,410 acres (5.7 km2) and the property was renamed Belair (sometimes written as Bel Air).

[11] Henderson sold the land along with two other parcels known as Woodcock's Range and Enfield Chase to two partners, Ogle, and Benjamin Tasker Sr. on March 30, 1737, for the sum of £500.

In 1747, Ogle returned to Maryland with his new bride[8] to occupy his new home which was "the grandest in the region" visible from much of the surrounding area and "affording its owners a magnificent, all-encompassing view of their plantation."

Ogle brought with him, two famous English horses and the first English-bred Thoroughbreds imported into Maryland, Queen Mab and Spark, both gifts of Lord Baltimore, establishing the Belair Stud.

At the age of 10, Benjamin Ogle was sent to England for formal education and returned 11 years later in 1770 to find Tasker's daughters and their husbands living in the estate.

[23] Belair, like other plantations, was "possessed of huge tracts of land but suddenly without the built-in workforce to make them productive, they were often unable to meet mortgage debts or to pay taxes."

[21] When tenant farmers moved in the mansion alongside Rosalie, she took them to court stating that she could not live in a house with people so far below her station.

[24] In 1898, Hardesty's land was surveyed to be 371.4 acres (1.503 km2) including the mansion and the stables and was purchased for $10 and an undisclosed sum by wealthy banker James T.

During this time, he developed a very close relationship with Saint John's College in Annapolis and was elected to its board of visitors.

[2] His nephew, wealthy lawyer and banker, William Woodward Sr. inherited the estate in 1910 and expanded the building in 1914 to a five-part house by the additions of two wings and hyphens.

[2][3] During this period, William opportunistically bought up adjacent tracts of land including purchases from the Magruder family[25] and the nearby Fairview Plantation of Oden Bowie and began developing the Belair Stud.

After his father's death, he took over operation of Belair for a brief period before he was fatally shot in his Oyster Bay, New York estate by his wife in 1955.

[27] By the time of Woodward Jr's death, the estate had grown back to 2,280 acres (9.2 km2); it was purchased at auction by Levitt and Sons in August 1957 for $1,750,000 (~$14.5 million in 2023).

Based on Palladian architecture stressing symmetry, the original structure has two long façades featuring a central door and balanced number of windows on each side.

[5] From the National Register of Historic Places Inventory Nomination Form: "The principal or garden façade faces south and is seven bays in length.

The entrance door of the south façade has a pediment supported by scroll brackets and trimmed with dentil molding and is framed by fluted pilasters.

The main entrance of the north façade has a simple frame with fluted pilasters, but is sheltered by a fine pedimented portico with dentil cornice supported by tapered columns with Ionic capitals.