What I came up with, in discussing my dilemma with friends and colleagues, was a two-step process. First, I would compile a preliminary checklist of all those immigrants who came to New England between 1636 and 1640. I would create this checklist by undertaking a systematic survey of all surviving records generated in New England for those years, and taking note of individuals who had not already been covered in the published Great Migration volumes. This first step is identical with the procedure I employed for the published volumes of sketches.
Second, I would merge this checklist with the list of sketches already created for the three volumes of Great Migration Begins and the seven volumes of the second Great Migration series. From this merged list of all Great Migration immigrants, I would create concise entries for each head of family or isolated individual, each entry to include a limited amount of information about the immigrant, including English origin (if known), year of arrival, and the best available treatment of the immigrant in the secondary literature.
For those persons in the checklist who arrived between 1620 and 1635, I would create entries by extracting information from the published sketches (and, when relevant, taking note of more recent research). For those who arrived between 1636 and 1640, I would create entries by adding to the checklist whatever additional data points were required to generate a useful entry, especially English origins. In this way, the resulting reference work would present enough information about every Great Migration immigrant to provide the researcher with an easy path to the best treatments of an immigrant of interest (or to indicate that no useful treatment yet existed).
As examples of my method, here is an updated entry for someone in The Great Migration Begins (see any of the earlier published Great Migration volumes for a key to abbreviations):
Thomson, James: Fishtoft, Lincolnshire; 1633; Charlestown, Woburn [GMB 1809-11; TAG 74:101-4].
Here is someone new to the series, first seen in 1637:
Martin, Ambrose: Unknown; 1637; Dorchester, Concord; not seen after 1642 [DTR 24, 28, 30; DChR 4; CoVR 2; MBCR 1:252].
Adapted from “Documenting New England’s Founders in The Great Migration Directory” in the Summer 2015 issue of American Ancestors magazine (a benefit of NEHGS membership). The Great Migration Directory will be published in June 2015.