Raman spectra from 600 to 1150 cm^-1 have been collected from wet-spun films of highly oriented CaDNA as a function of relative humidity (rh). Particular attention was paid to the Raman modes at 834 and 807 cm^-1; the presence of these modes indicates that the DNA backbone is in the B or A conformations. Though the B conformation is usually found only under conditions of high hydration in such wet-spun films, CaDNA is found to remain in the B conformation down to 75% rh. These results are consistent with the hypothesis that intermolecular bonds in ordered samples of DNA are critical for the stabilization of the A conformation of DNA.