  The Cosmic Gamma-ray Background (CGB) in the MeV regime has been measured
with COMPTEL and SMM. The origin of the CGB in this energy regime is believed
to be dominated by gamma-rays from Type Ia supernovae. We calculate the CGB
spectrum within the framework of FRW cosmology as a function of the cosmic star
formation rate, SFR(z). Several estimates of the SFR(z) have been reported
since the pioneering work of Madau et al. Here we discuss observational
constraints on SFR(z) derived from models of the CGB. In particular, we
consider the SFR obtained from Gamma-Ray Burst observations, which increases
dramatically with redshift beyond z ~ 1 in contrast to most estimates which
saturate or show a mild increase with redshift. Gamma-ray bursts may be the
most powerful tracers of star formation in the early universe and thus provide
signposts of the initial epoch of element synthesis. The star formation rate
implied by GRB statistics results in a gamma-ray background that matches the
observations more closely than that inferred from other tracers of star
formation. This may provide some support for the GRB/SFR-paradigm, which in
turn promises a powerful diagnostic of star formation, and thus cosmic chemical
evolution, from the era of Population III stars to the present.
