  The realistic free fermionic models have had an intriguing success in
explaining different properties of the observed particle spectrum. In this
paper we discuss in some detail the anomalous U(1) symmetry which exists in
these models. We study the properties of the anomalous U(1) in both the more
realistic NAHE--based free fermionic models and those in a general NAHE class.
Appearance of an anomalous U(1) in the more realistic NAHE models is shown to
be an effect of reduction of world-sheet supersymmetry from (2,2) to (2,0). We
show, however, that in more general (2,1) and (2,0) models, all U(1) can remain
anomaly-free under certain conditions. Several phenomenological issues related
to the anomalous U(1) are discussed. In particular, we note that in some
examples the anomalous U(1) arises from the breaking $E_6 -> SO(10) X U(1)_A$,
resulting in $U(1)_A$ being family universal.
