This treatise is a compendium of papers based on invited talks presented at the American Chemical Society Symposium on Electroactive Polymers which covered nonlinear optical polymers and conducting polymers, the common denominator being the correlated pi-electron structures. The improved understanding of the consequences of pi-electron delocalization upon nonlinear optical properties and charge carrier dynamics has laid the foundation for the rapid development and application of the electroresponse of conjugated polymers. As a result, the area of electroactive and nonlinear optical polymers...