The diaries of Rev. Frederick Krecker cover a span of almost fifty years (1838-1888). There are twenty-five (25) individual volumes. The reveal in a very personal manner the lifetime experiences of an itinerant evangelical preacher in Pennsylvania's Lehigh Valley. Among the topics discussed are the conversion numbers of prospective new members to his congregations; a highly detailed record of the seasonal weather paterns; a recounting of the challenges in traveling from one samll town to another on very basic roads in the worst of weather conditions, as well as a heartfelt description of the uttler loneliness he must cope with in his service to God.

The earliest volumes in these journals were written in German, but Krecker switched to English when his wife, Isabella, complained to him that she could not read German, their native language, well enough to comprehend his writings. The English use started in the sixth volume in 1848.

The diaries of Krecker record the ordinary work of an itinerant preacher who pastors to his congregations and the experiences of life in mid 19th century Pennsylvania in a way not too dissimilar to many of his contemporaries.