The scale and degree stylistic detailing of Upper Marlboro's  existing residential architecture is reflective of ownership and occupation by members of the middle- to upper-middle classes. The larger town lots are occupied by relatively large and well-built dwellings exhibiting stylistic detailing of the Greek Revival, Gothic Revival, Queen Anne abd Colonial Revival styles. These houses are mainly two and two and one-half stroies in height with the exception of Kingston (circa 1730), which stands one and one-half stories tall. The Tudor style and the American Foursquare form, dressed in Colonial Revival stylistic detail, are also represented, as are front-gable and side-gable cottage forms. Structural systems and exterior materials include clapboard, replacement aluminum, or vinyl siding over wood fram, as well as brick and concrete masonry.
From the time it was established until early in the 20th century, the name of the town and district was spelled Upper Marlborough. Over time it came to be abbreviated to Upper Marlboro and is consistently spelled that way today.
The road which connected Upper Marlboro and Queen Anne was established early in the 18th century. In 1706, by act of the General Assembly, 6 towns were established in ten year old Prince George's County. Two of these six were Queen Anne on the Patuxent and Marlboro on a bend of the Western Branch at its confluence with the Collington Branch. At the time of the establishment of Prince George's County in 1696, Charles Town on the Patuxent (at the mouth of the Western Branch) had been designated as the county seat. After the establishment of Marlboro, Queen Anne and the other four port towns, business at Charles Town began to decline. County Court records indicate the growth of business and traffic in both Marlboro and Queen Anne. The opening of an ordinary in Marlboro in 1703 and at Queen Anne in 1711, and the repair of the road west of Queen Anne in 1713, testify to increasing activity in the two towns. By 1718, Marlboro had become such an active center that the inhabitants petitioned to have the County Courthouse moved there from Charles Town. The General Assembly consented to the move, and the Court met for the first time in 1721 in Upper Marlboro (so called by this time to distinguish it from Lower Marlboro in Calvert County). In 1726, a ferry was established at Queen Anne to carry passengers between Prince George's and Anne Arundel counties, and the Queen Anne ferry became the most frequent crossing point for traffic between Annapolis, the provincial capital, and Upper Marlboro.