The oldest remaining house in Los Angeles is the Avila Adobe located on Olvera Street (built in 1818). It is not, however, the oldest remaining house in Los Angeles County. Shane Kimbler, a Bell Gardens history enthusiast, wrote that early colonist Francisco Salvador Lugo and son Antonio María Lugo began construction in 1795 (or 1771?) on what is now known as Casa de Rancho San Antonio or the Henry Gage Mansion. The house is located at 7000 East Gage Avenue in Bell Gardens. It was built to qualify the younger Lugo, a former Spanish colonial soldier, for a land grant from the Spanish crown. In 1810, Antonio María Lugo completed the house and received the grant, naming his new grant Rancho San Antonio. The ranch eventually grew to encompass 29,513 acres (119.43 km2), including what are now the cities of Bell Gardens, Commerce, and parts of Bell, Cudahy, Lynwood, Montebello, South Gate, Vernon and East Los Angeles. When California became part of the U.S. in 1850, Lugo, as did all recipients of Spanish/Mexican land grants, began losing portions of his land to the growing population of Anglo newcomers. The ranch adobe, however, continued to be owned and used by the Lugo family.
By 1865, most of the Lugo ranch, divided among five sons and three daughters, had been sold off for as little as a dollar per acre. The original adobe ranch home, however, remained in the family. In 1880, attorney Henry Tifft Gage, a transplant from Michigan, married one of Lugo’s great granddaughters, Francis "Fanny" Rains. The original adobe ranch home was gifted to Gage as a wedding dowry and it became known as the Gage Mansion. When Gage acquired the mansion he worked very extensively to restore the heritage farmhouse of early Los Angeles. In 1898, Gage was elected to become the 20th governor of California. He served in that office from 1899 to 1903. In 1910, he was appointed by President William Howard Taft to serve as U.S. Minister to Portugal. He resigned after only one year due to his wife’s health problems. Gage lived in the abode ranch house until his death in 1924.
A century later, the Gage Mansion was all that remained of the once great Rancho San Antonio. In 1983, the Casa Mobile Home Park, a cooperative of mobile home owners renting lots on the property, purchased the land and the house from their ailing landlord. Although they were aware of the historical significance of the old house, they had no means of maintaining it. In 1987, then Bell Gardens City Councilwoman Letha Viles began working to get the house listed on the state historical registry, making it eligible for maintenance grants. It is now listed as California Historical Site Number 984.