William Douglas promoted the subdivision and handled the early sales of lots. A newspaper announcement heralded the opening of the Kensington Park subdivision for lot sales on November 25, 1910. The owners had managed to convince the officials of the San Diego Electric Railway company to extend the Adams Avenue trolley line into Kensington Park in time for the opening. The first houses began to be built in 1910 and were all of the Craftsman style. The original Kensington Park subdivision stretched from Ward Canyon on the west (now SR-15), to County Line Road (now 42nd Street) on the east, and from Monroe Avenue on the south to Jefferson Avenue on the north (now Alder Drive). Kensington Park was annexed to the City of San Diego in 1952.