In the aftermath of the Mexican-American War, steamships plied the Lower Colorado River from the Gulf of Mexico to the present site of Hoover Dam. They were instrumental in fortifying southern Arizona and southeastern California, displacing the region's native inhabitants, facilitating westward migration, and appraising the terrain. During these years, steamship owners, operators, and passengers announced, enforced, and negotiated peripheral conflicts attending continental expansion. The Colorado River demarked a line of sovereignty and a line of defense, as well as a line of commerce. The relatively unexplored history of steamship navigation consequently illuminates the river's role in solidifying and regulating the borderlands, and, more significantly, its centrality to the river's larger narrative.
University of California Press