“Systems of Subordination” utilizes diplomatic correspondences from British and American consuls in the Pacific to explore these thickening networks of governance in an age of imperial expansion. It views the convergence of private and governmental interests through the lens of Chinese immigration, and diplomatic interventions from the American consuls stationed in Melbourne and Hong Kong and the British consul in San Francisco. This dissertation argues that print media and diplomacy—respectively framed as the de facto and de jure pillars of empire—shaped the coeval development of race-based laws and ideologies within, and between, British and American empires in the gold-rush Pacific. Moving beyond the comparative, it explores how rapid developments in transportation and communications technologies connected people, ideas, and laws between California and the British Empire in Hong Kong, Australia, and British Columbia.