The NCSU maize breeding program is one of the few remaining public maize breeding programs in the U.S. that is actively releasing inbred lines. In the past 40 years 157 NC inbreds have been developed and released. For over 20 years there has been considerable emphasis on breeding with exotic germplasm. This program represents an important resource for maize improvement and diversity in the U.S. Phenotypic and yield trial performance data are available for all of the NC maize lines, either in the public domain or upon request. However, there has been little or no genetic characterization of the NC maize germplasm pool, aside from a few studies of isolated groups of lines, mostly for QTL mapping studies. While detailed pedigree records have been kept, they are shrouded in 37 years of nursery books, an enigma that only those intimately familiar with the program can decipher. The genetic resources of the NC maize germplasm pool can be more fully utilized by breeders and geneticists if more information about line development and line genetics is available. Thus, there is a need for systematic characterization of this unique collection of germplasm. We are conducting a genetic characterization of the NC maize germplasm pool. We are calculating coefficients of coancestry based on pedigree data and molecular marker data. Principle component analysis has been employed using this coancestry matrix and lines cluster in three main groups, Stiff Stalk, non-Stiff Stalk, and Tropical. We are also assessing changes in allele frequency through multiple cycles of selection and identifying putative genomic regions under selection.