The Kalorama area was primarily rural until the close of the 19th century, lying northwest of the original limits of Washington City from L'Enfant's original plan. In 1795, Gustavus Scott, a commissioner for the District of Columbia purchased the property, which had been a portion of Anthony Holmead's "Widows Mite" holdings. He constructed a large, classically styled house at 23rd and S Streets, which he named "Rock Hill". In 1803 Margaret Scott the wife of Gustavus Scott sold the property to William Augustine Washington. In 1807, the noted poet Joel Barlow bought the property and renamed it "Kalorama," which translates from Greek as "fine view." Barlow lived in the home until shortly before his death in 1812. Barlow commissioned Capitol architect Benjamin Latrobe to enlarge the house and elevate its design. Kalorama (the residence) was destroyed by a fire during the American Civil War while it was used as a Union hospital. The residence was rebuilt and returned to a single-family home until 1887, when it was leveled by the District of Columbia government for the extension of S Street NW.
In the early 1880s, the Kalorama area, being located beyond Boundary Street (now Florida Avenue) and thus outside the city limits, which had hithero remained primarily undeveloped, began to be subdivided for urban development. In 1893 Congress ordered L'Enfant's design of the city of Washington extended outward to include the rest of the District. Existing developments were exempted, which is why Kalorama is one of the few portions of D.C. that does not comply with the city's grid system for streets. Two high bridges over the deep gorge of Rock Creek became important to the development of both sides of Kalorama in this period, the Calvert Street bridge (since replaced by the Duke Ellington Bridge), built in 1891, and the Taft Bridge (on Connecticut Avenue), built in 1907.
The Westmoreland, located at 2122 California Street NW, was built in 1906. The building originally opened as a rental property in 1906 and was converted to a co-op in 1948. The building was designed by architects Edgar S. Kennedy and Harry Blake in 1905.
The Kalorama Triangle is a residential enclave of Adams Morgan, located in Northwest Washington bounded by three major thoroughfares: Connecticut Avenue, Calvert Street, NW and Columbia Road. Kalorama Triangle is in the service area of Advisory Neighborhood Commission 1C, the Adams Morgan Advisory Neighborhood Commission, and is represented by the commissioners for 1C02.
The neighborhood is served by mass transit, with the Woodley Park Metro station across the Taft or Duke Ellington Bridge, the 90/92/96/97/X3/L2 Metrobus lines and one of the DC Circulator lines stopping along its northern border (Calvert Street), the L1 Metrobus line (rush hour only) stopping along its western border (Connecticut Avenue), and the H1/42/43 Metrobus lines (H1 and 43 being rush hour only) stopping along its south-eastern border (Columbia Road).