The similar pronunciation of the T and the D at the beginning of German surnames creates an interchangeable sound, making it imperative for family history researchers to check the records of surnames beginning with each of those letters. While searching for Trexler family records, the author was able to identify 173 families with identical of similar surnames. The greatest variation in the subject surname spellings was found in 18th century records, which are the focus of this work. By the early 19th century, families and individuals had developed a pattern of consistent use of their chosen surname spelling. The purpose of this work is to help individuals researching these and similar surnames to identify target individuals easily, regardless of the surname changes that resulted as the family evolved. Therefore, this work does not include extensive family histories, but it does give actual source records from which 173 individual family units have been documented. A researcher interested in a particular individual or family unit will be able to quickly eliminate a great deal of background research, and he or she can concentrate on the particular geographic area in which the individual is found and the variations in surname spellings under which they are found. Supplemental sections in this book include cemetery, census, church, chancery, city directory, probate, wills, distributions, immigration, deeds, land, tax records, marriage records, Revolutionary War, War of 1812, militia records, newspaper references and miscellaneous records which did not fit into one of the previously defined groups. They include both published and non-published sources with all variations of the subject surnames. They are grouped under each heading by geographic locality, followed by the name of the record, and then by the name of the individual in the record. There is a full name index as well as a general index.