  Phenomenological parameterizations of proton and neutron polarized structure
functions, g1p and g1n, are developed for x > 0.02 using deep inelastic data up
to ~ 50 (GeV/c)**2 as well as available experimental results on photo- and
electro-production of nucleon resonances. The generalized Drell-Hearn-Gerasimov
sum rules are predicted from low to high values of Q**2 and compared with
proton and neutron data. Furthermore, the main results of the power correction
analysis carried out on the Q**2-behavior of the polarized proton Nachtmann
moments, evaluated using our parameterization of g1p, are briefly summarized.
