At the beginning of the twentieth century, as international competition in astronomy increased, French astronomers were having serious doubts about their international supremacy. Now challenged by the development of interdisciplinary specialties such as astrophysics or geophysics, celestial mechanics had traditionally conferred most of its prestigious status to French astronomy. Considering they were unable to make important contributions on the international scene, a marginal community of French astrophysicists publicly lamented their lack of instrumental resources or the inadequacy of existing ones, as well as poor institutional support. In this paper, I examine the way in which leading French astrophysicists looked at American astronomy. Leading expeditions to the U.S. in the first two decades of century, they wrote reports about the organization of U.S. observatories and shared a fascination for Californian ones. In particular, all believed that George Hale's Mount Wilson Observatory was the only place in the world where astrophysics could really develop: a new "astronomical Eldorado" (as Pulkovo and Greenwich had been before). Back home, they sought to import the U.S. research system to transform the French astronomical community as a whole. The invocation of American astrophysics was a pretext for local issues: a prism that coloured national claims.