  We present a measurement of the W boson mass using data collected by the D0
experiment at the Fermilab Tevatron during 1994--1995. We identify W bosons by
their decays to $e\nu$ final states. We extract the W mass, M(W), by fitting
the transverse mass and transverse electron momentum spectra from a sample of
28,323 W to $e\nu$ decay candidates. We use a sample of 3,563 dielectron
events, mostly due to Z to ee decays, to constrain our model of the detector
response. From the transverse mass fit we measure M(W) =
$80.44\pm0.10(stat)\pm0.07(syst)$ GeV. Combining this with our previously
published result from data taken in 1992--1993, we obtain M(W) $= 80.43\pm0.11$
GeV.
