Izapa, a Late Preclassic regional center located in southern Mexico, was heavily excavated by the New World Archaeological Foundation from 1961-1965. However, much remains unclear regarding the details of those excavations, specifically in regards to Group B. In this thesis I hope to present important details derived from those excavations in a way that is meaningful and useful. The purpose of this thesis project is to: (1) reconstruct the excavation history of Izapa Group B, (2) to provide a reconstruction of Group B's architectural history as revealed through the excavations, and (3) to identify and present descriptions of the contents and context of the plaza's numerous burials and offerings. Group B, containing the oldest known constructions at Izapa, is a special place and vital to understanding the growth and development of Izapa as a regional center.