The Los Angeles Railway Company was formed in 1895 “to succeed to the property and franchises” of the bankrupt Los Angeles Consolidated Railway. The new company began immediately the electrification of the earlier company’s cable lines. This was the beginning of the expansion and modernization of the system. Three years later the company was completely reorganized and enlarged to include a number of other smaller street railway companies. At this time, Henry E. Huntington became involved in street railway operations in Southern California, serving as the new company’s first president.

During the first decade of the 20th century, Hunting-ton was the major force in building a first class transit system in Los Angeles. The expansion of Huntington’s transit systems, which also included the Pacific Electric Railway, created the need for increasing sources of electrical power. A number of new substations were built at this time to meet the growing needs of electrical rail transportation. The Plaza Substation was one of the power producing facilities built during this period of rapid expansion of Southern California’s electric railway systems.

By 1904 the company had two electrical power substations in operation: the University Substation (1903) and the Huron Substation (1903-04). These two substations, however, were not able to keep up with the power demands of the rapidly expanding transit system. In December of 1903, the Los Angeles,Railway Company purchased a parcel of property on Olvera Street just north of the Plaza from Mrs. Luisa Olvera de Forbes. Construction of the Plaza Substation followed on this site. The precise date of construction is not known, although the operation of the substation can be documented for 1906. Construction, therefore, occurred sometime between December of 1903 and 1906. The style was similar to other electrical railway facilities being constructed during the same period, generally following the “Mission lines of architecture”.

In 1906 two 1000 kw motor generators were installed, followed in 1907 by a third of similar output. In 1920, two rotary converters, each with a capacity of 1500 kw, were installed. The Plaza Substation served the power production needs of much of the downtown area’s streetcars, and was the largest power producer of the Los Angeles Railway Company’s substations. By the time electric streetcar service ended in Los Angeles in March of 1963, the Plaza Substation had been phased out and its machinery removed.

The Plaza Substation is an important landmark in the history of transportation in Los Angeles. It is one of the last four remaining substations of the original fourteen built by the Los Angeles Railway Company, and is the only substation remaining in the central city. It is presently facing an uncertain future; it does not meet present seismic code requirements, and has been proposed for demolition.