The data are arranged by year and type of movement, including commitment, return to prison as a parole violator, parole, suspension from or reinstatement on parole, discharge, death, and execution. The record for each inmate contains information on age at admission, race, marital status, education, military history, occupation, number of prior arrests, escape record, date and type of release, and parole violations. The data set contains 16 files, each with a logical record length of 90 characters. A discussion of the data set explains how the records are arranged by year and type of movement, gaps and changes in the data set over time, the coding conventions used, and the characteristics of each major file.