  Evidence for pair production of a new particle consistent with the Standard
Model top quark has been reported recently by groups studying proton
anti-proton collisions at 1.8 TeV center of mass energy at the Fermi National
Accelerator Laboratory. In this paper we review the history of the search for
the top quark in electron positron and proton anti-proton collisions. We report
on a number of precise electro-weak measurements and the value of the top quark
mass which can be extracted from these measurements within the context of the
Standard Model. We review the theoretical predictions for top quark production
and the dominant backgrounds. We describe the collider and the detectors that
were used to measure the pair production process and follow on to describe the
data from which the existence of the top quark is evinced. Finally, we present
possible measurements that could be made in the future with more data,
measurements of quantities that would confirm the nature of this particle, the
details of its production in hadron collisions, and its decay properties.
