Using personal and family letters written between 1876 and 1896, this article charts the life of a post-conquest Californiana, Josefa del Valle Forster (1861–1943). It argues that the industrial and commercial development that took place in Southern California after 1850 reconfigured family relationships and gender dynamics, shifting understandings of intimacies for del Valle Forster. This discussion of an era and community often overlooked in California history contributes to a fuller picture of how Californianas experienced the late nineteenth century, and it highlights the significance of letters as a historical source for understanding how individuals and families negotiated the transformations wrought by war and conquest.