There are three published sources for transcribed and abstracted probate records of early Essex County: Essex Institute of Historical Collections [EIHC], published from 1859 to 1993, which we discussed earlier regarding criminal and civil court records; Essex
Antiquarian (1897–1909), a magazine that reprinted many abstracts published in EIHC; and The Probate Records of Essex County, Massachusetts, published in 1916, also based on work first presented in EIHC.
To see original probate files and indexes, one traditionally had to travel to the county courthouse in Salem because a published index to the file numbers for Essex County probates was not done until 1987. Today, we are blessed with direct access to digital images of original files:
Essex County, MA: Probate File Papers, 1638–1840, in the AmericanAncestors database, and Massachusetts, Essex County, probate records, 1638-1881 at FamilySearch.org. These are the same images, but the AmericanAncestors database provides an index with direct links to each file.
Digital images of original records, which are made from microfilm images, are often both a blessing and a curse. Faded ink, bad handwriting, torn pages, missing chunks, and sometimes empty files can greet the researcher. The next step, therefore, is to look at the copies that were made from the file documents: Essex County, Massachusetts, probate records and indexes 1638-1916. The first set of records in this series is that of the docket book indexes, which present estates arranged alphabetically by name and give both the file number to the papers and the volume and page to the copybook.
The second set of records in this list is that of the images from the copybooks. It is important that both original and copybook versions be accessed, not only because the copy books may be more legible than the originals, but also because the two sets often contain different items. Documents that appear in the copy books may be missing from the probate files, and files may include additional documents not copied into the books, such as receipts of heirs, accounts of executors, records regarding disputes, etc.
With all these resources, Essex County researchers have little excuse for not thoroughly
accessing probate records, lucky you.
 Note: the abstracts in each of these sources are not always identical, sometimes because of copying errors or omissions, sometimes because they were made by different transcribers, but in the end requiring that researchers compare all versions with each other and with originals when available.
 Melinde Lutz Sanborn [now Byrne], transcriber, Essex County Massachusetts Probate Index, 1638-1840 (1987).
 Just to make things confusing, probate “file papers” (the original papers) are often also cataloged as “records” (which, technically, are the copy book transcriptions from the original papers).