The rapidity distributions of W and Z bosons produced in proton
anti-proton collisions at CDF are presented.  The rapidity distribution of Z
bosons, measured for the first time over the entire kinematic range, is better
described by NLO QCD (and also by QCD with gluon resummation) than by leading
order QCD.  The W charge asymmetry data as a function of rapidity strongly
constrain the ratio of d and u quark momentum distributions in the proton over
the x range of 0.006 to 0.34.  The W data are used to rule out recently
proposed models for charge and flavor symmetry violation of the sea quark
distributions in the nucleon.