Obtaining the Land
The principal portions of San Marino were included in a Mexican Land Grant in 1830 to an indigenous lady named Senora Victoria Reid, the widow of a Scotsman. She named her rancho “Huerta de Cuati”. Prior to this grant, the area was part of the San Gabriel Mission (the "Old Mill" was the grist mill for the mission), and before that was occupied by indigenous people with their village located at what is now Huntington School

Naming the Land
In 1852, Don Benito Wilson took possession of Mrs. Reid’s rancho. Later, Wilson deeded a portion of his land to his daughter Maria de Jesus, known as Sue. Sue married J. de Barth Shorb, who renamed his rancho after his grandfather's plantation in Maryland, which in turn had received its name from the Republic of San Marino, in Italy

The San Marino Republic was named after a Dalmatian stone-cutter, by the name of Marino, who fled nearly 1,600 years ago from his home on the Dalmatian coast at the time of a Turkish invasion, and took refuge among the rocky crags of Monte Titano, which commanded a view of the Adriatic Sea.