Darnall’s Chance is a heavily restored early brick manor house, preserving Upper Marlboro’s most significant landmark. One of the earliest substantial houses in the region, it was built as a five-bay, one-and-a-half-story dwelling of Flemish-bond brick with quoining, a central pavilion, paired flanking chimneys, and a jerkinhead roof. Exemplary of the period, the generous 55 × 35-foot house was described in 1760 as a four-room plan with broad center passage, a full cellar with kitchen, and a fireplace in each room. It was built for Scottish immigrant and prominent merchant James Wardrop on land once owned by Henry Darnall, a relative of the colonial proprietors, the Calvert family.
By the mid-nineteenth century, the house was remodeled as an Italianate Villa and raised to a full two stories; a stuccoed facade was applied. It was extensively restored by owners M-NCPPC in 1986, which reconstructed the original roof, chimneys, and leaded casement windows. The property includes a burial vault dating to c. 1775.