 A network of railroads spread throughout northern California, and in 1887, a rail link was completed to the Pacific Northwest.Almost all of these railways came under the control of the Southern Pacific Railroad, headquartered in San Francisco, and San Francisco continued as a financial and cultural center.Substantial tensions during this era included nativist sentiments (primarily against Chinese immigrants), tensions between the increasing power of the Southern Pacific Railroad and small farmers, and the beginnings of the labor union movement.