The unitary group and the electron correlation problem

A survey is given of the background and development of the unitary group approach and its graphically-based implementations for electronic structure calculations. The nature of the unitary group and its relationship to the electronic many-body problem are briefly discussed, as well as the reasons, purpose, and methodology of its application to this problem. As much as possible, this discussion is on a mostly intuitive, non-technical level. Finally, recent accomplishments and expected future developments are briefly mentioned.