The data came from records at the University of Georgia combining three separate groups of records and from newspaper reports in primary archives at the Library of Congress and libraries in Louisiana. The analysis focused on the size and class composition of the lynch mob, the racial composition of the lynch mob, the race of the alleged victims, the mode of death, indications of cooperation by law enforcement officers, and the reactions of local whites and African Americans. Results indicated that a significant percentage of the 19th-century lynchings committed by both African Americans and whites is better understood as a traditional type of self-help justice than as a form of racial domination. However, after 1900, informal execution in Louisiana became progressively more racist in its application, and African Americans virtually disappeared from the active ranks of lynch mob participants. Although the racial domination model successfully explains the majority of Louisiana lynchings in the 20th century, extralegal execution as a form of social control served different purposes that varied over time and for different segments of the southern population. Tables, map, footnotes, and 50 references (Author abstract modified)