In the closing decades of the 19th century, tens of thousands of European immigrants and Southern blacks flocked to the steel towns of Pennsylvania, lured by relatively high wages in the mills. The social structure of this industrial order - how it was formed and how it changed - is the subject of this study. Officials of the steel company, professionals and merchants dominated the political and social life of Steelton, a mill town of 13,000 in central Pennsylvania. This community elite was white, Protestant and Anglo-Saxon, while the lower class consisted of the unskilled and semiskilled, principally Slavs, Italians and African-Americans. Contrary to the view that, after early struggle and hardship, successive ethnic groups inevitably prospered and merged in the new industrial order, the pattern of community development in Steelton shows that ethnic groups remained distinct for decades, both on the job and in residential neighbourhoods. This situation changed only after 1940, when immigrants and blacks supported the steelworkers' union that finally broke the domination of the old stock. For his study of a community under the impact of industrialization, John Bodnar has used census data, local marriage and tax records, and interviews with first- and second-generation immigrants.