This is a record of baptisms performed by Father Helbron in his missionary travels in the seven Western Pennsylvania counties of Westmoreland, Fayette, Washington, Greene, Allegheny, Butler, and Armstrong. The Helbron register is apparently the first written record of sacramental ministrations in these outlying areas of Pennsylvania, and it is important not only because of its priority but because it comprises, in many cases, the only extant records of the Irish and German Catholics who settled this region. Over 1,500 baptisms are recorded, each entry typically giving the child's name, the dates of birth and baptism, and the parents' and sponsors' names. In all, the complete body of baptisms references some 6,000 persons.