The Californian Gold Rush stimulated expectations of discovering similar riches in Baja California, a territory conceived as possessing similar geological constitution. During those years, a few mining enterprises were established, such as San Rafael (1850), La Candelaria (1851), Rancho San Isidro (1853) and San Jacinto (1853), but all of them resulted in small deposits. In the 1860’s, however, bigger enterprises, such as Triunfo Gold and Silver Mining Company, Tesoro Silver Mining Company and Santa Cruz Silver Company, were founded. Their success promoted immigration from entrepreneurs and mining workers, causing fear of annexation plans from the U.S.A government.

President Juarez decided to regulate the progressive immigration by means of a colonization lease that promised land and tax exemption to an American company, required to undertake the scientific exploration and colonization of a long share of Baja California’s territory. In exchange, the Lower California Company promised to include a third of Mexican citizens into the potential colonists.

Scientific exploration followed and geological inspection was entrusted to William More Gabb (1839-1878), an American geologist born in Philadelphia, who had already participated in different geological expeditions in the West Coast. Gabb was a disciple of Martin Hans Boyé (1812-1907) and James Hall (1811-1898), whose influence can be confirmed in Gabb’s large scientific production, comprehending geological exploration of Peru (1867), U.S.A.’s West Coast (1867), Santo Domingo (1871, 1872), Curazao (1873) and Costa Rica (1874, 1875, 1898).

This paper proposes to analyze Gabb’s expedition in Baja California, which was executed from December 1866 to April 1867, and resulted in several scientific papers and journalist reports. The former dealt with Baja California’s botanical, zoological, paleontological, geological and ethnological resources, while the latter speculated on its possible annexation to the U. S. A.

Therefore, Gabb’s expedition produced scientific knowledge impregnated with political meanings, that were influential in annexation debates in the years that followed.

This presentation is based on work co-authored by Óscar Moisés Torres Montúfar.