It is well known that the compositions of glasses quenched by contact with seawater are a good guide to unmodified erupted liquid compositions. We present here an updated version of the Smithsonian Abyssal Volcanic Glass Data File (AVGDF) of the major and minor element compositions of such glasses mainly from seafloor spreading centers determined by electron microprobe analyses. These data help define the major and minor element compositions of the most abundant terrestrial volcanic rock. The AVGDF contains 9050 individual glass analyses along with the sample donor, latitude, longitude, depth, tectonic setting, ship-cruise-dredge, and the major and minor elements SiO2, Al2O3, FeO*, MgO, CaO, Na2O, K2O, TiO2, P2O5, and MnO (for some samples). The samples are from 664 Atlantic, 28 Caribbean, 89 Indian, and 1304 Pacific localities. These include dredge, submersible, DSDP and ODP sites. The data serve to (1) map out and model processes associated with magma generation and fractionation in the asthenosphere and lithosphere beneath seafloor spreading centers and (2) as an educational aide for exercises in the use of such data at the graduate and undergraduate levels in geochemistry, geophysics, and igneous petrology. The extensive polished sample collection is available on loan for additional petrographic (in reflected light) or microbeam analyses.