Final answer:
While not explicitly named, large corporations and individuals like Leland Stanford and John D. Rockefeller's Standard Oil had major influence over California politics in the late 19th century, amid rapid industrialization and the prevalence of trusts.
Step-by-step explanation:
The corporation that dominated California politics in the late 19th century was not explicitly named in the provided information. However, it is well documented that large corporations and business tycoons such as those in the railroad industry and the oil industry had significant influence during this era. Notably, figures like Leland Stanford, who was involved with the Central Pacific Railroad, were instrumental in shaping California's economy and politics. Standard Oil, controlled by John D. Rockefeller, is another example, which had a near-monopoly on the nation's oil refineries at the time. These corporate influences are an essential aspect of the broader political and economic context of the late 19th century, also marked by rapid industrialization and the rise of trusts, ultimately leading to the Progressive Era's regulatory reforms.