Historical Background
The Del Valle and Forster families were prominent Californio landowners during the 19th century. John F. Forster was the son of California's largest land owner Don Juan Forster who owned Rancho Santa Margarita located in present day Orange County. Reginaldo and Josefa Del Valle were the children of California politician Don Ygnacio Del Valle who owned Rancho Camulos in present day Ventura County. Reginaldo Del Valle practiced law and was elected to the California State Senate. The marriage between Josefa Del Valle and John F. Forster joined these two prominent families together.
From the guide to the Forster-del Valle family papers, Bulk, 1880-1930, 1804-1975, (Special Collections and Archives, University of California, Irvine Libraries)