Brian C. Hall Coherent states, Yang-Mills theory, and reduction (78K, Latex) ABSTRACT. This paper explains the ideas behind a prior joint work of the author with Bruce Driver on the canonical quantization of Yang-Mills theory on a spacetime cylinder. It explains how the generalized Segal-Bargmann transform for a compact Lie group (or generalized coherent states) arises from the ordinary Segal-Bargmann transform for the space of connections, after gauge symmetry is imposed.