Uncertainties in 21 centimeter Redshifts. I. Data

High-precision data on the 21 cm redshifts, profile widths, and shapes of 625 galaxies are presented. Each galaxy is listed in a cross-identification and morphology table. We also give high-resolution spectra for each galaxy. Internal redshift consistency is roughly 1 km s^-1^ for galaxies for which our S/N is above 15. No systematic effects have been found which might influence the observed redshift quantization at 72.5 km s^-1^ or its submultiples.