  We present the first-ever description the world data on the $g_1^{p,n}$
structure function at small Bjorken $x$ using evolution equations in $x$
derived from first principles QCD. This is a Monte-Carlo analysis within the
JAM global framework that allows us to fit all existing polarized DIS data
below $x<0.1$ as well as predict future measurements of small $x$ $g_1^{p,n}$
at the EIC. This is a necessary step in determining the quark helicity PDFs
and, ultimately, the quark contribution to the proton spin.
