Genealogical Databases: Key Tools for the History of Transnational Migratory Trajectories

Genealogical research has expanded rapidly over the last twenty years, with the emergence of websites that provide online access to large quantities of archival documents. These websites offer gigantic databases for use by genealogists, but they have proven particularly useful in historical research trying to reconstruct the migratory journeys of individuals or families. These databases can bring together sources of a different nature from across the globe via the connecting thread of biographical itineraries, and as such are a key tool in reconstituting transnational trajectories. They therefore help move beyond the “methodological nationalism” denounced by numerous authors, who have questioned the relevance of a nation state’s borders as a preferred unit of analysis.[1]On methodological nationalism, see especially Andreas Wimmer and Nina Glick Schiller, … Continue reading Transnational history invites us to decompartmentalize viewpoints and hence sources, and aims to reveal connections and circulations beyond state borders, with the historian becoming, to use Serge Gruzinski’s metaphor, an electrician repairing the wires cut by national history.[2]Serge Gruzinski, Les quatre parties du monde. Histoire d’une mondialisation (Paris: La … Continue reading Genealogical databases are key in this respect, for they do not limit themselves to “national” entries like most archival centers, instead bringing together documents from different countries.

A Wide Range of Sites for a Single Objective: Exploring One’s Family History

Today there are many genealogy websites, including the French sites Geneanet and Filae, the Israeli site MyHeritage, and the American sites Ancestry, FamilySearch, and JewishGen. This is not an exhaustive list, but it gives an idea of the wide range of offerings. Some sites are free, such as FamilySearch and JewishGen, while others require a paying subscription for full access to their functionalities, such as Geneanet, Filae, MyHeritage and Ancestry. While they are all based on the same objective of genealogical research, and provide access to digitized and indexed archival documents for this purpose, they nevertheless differ in how they constitute their collections, with some largely relying on a collaborative aspect through contributions from their members, and others emphasizing partnerships with public and private archival centers.  In any event, they all combine in varying degrees these two methods for collecting documents. Finally, despite criticism and debates on this subject, some of these genealogy websites have had great success offering a genealogy research service using DNA analysis.[3]For example, in 2019 MyHeritage generated $70 million in revenues using DNA tests. This is especially true of Ancestry, MyHeritage, and Geneanet, which has offered a “DNA file uploading” service on its site since February 2020.[4]The practice of “recreational genetics” is illegal in France, although it is possible to take … Continue reading

Let us consider the example of Geneanet, a collaborative database primarily compiled by its members, and focusing primarily on France.  The site was launched in 1996 under the name LPF, Liste des Patronymes de France (List of French Patronyms). Its objective was to share genealogical trees, and to enable the comparison and cross-referencing of hundreds of thousands of data items in an effort to pool together research among amateur genealogists. In 2006 the site recorded over 300,000 unique visitors, reaching one million in 2011. In 2019, it claimed to have four million visitor per month, and over six billion individuals listed in genealogical trees, digitized certificates, postcards, family photos, and civil registry extracts.[5]This number should be put into perspective due to many duplicates: there are not six billion … Continue reading Thanks to document indexing, searches can be conducted by keyword, family name, and geographical location.

Screenshot from Geneanet © all rights reserved

Launched the same year as Geneanet, Ancestry was originally a project for the Mormon community in the United States. The site gradually signed agreements with national and local archives throughout the world to digitize part of their collections and make them available online. It notably collaborated with the national archives of the United States and United Kingdom, as well as local associations. In 2008 Ancestry established a partnership with the Centre généalogique et héraldique de la Marne to give online access to the index of records collected conducted by its members using civil registries conserved in French departmental archives.

Screenshot of an Ancestry search form © all rights reserved

In November 2018, Ancestry claimed to have over 3 million subscribers, 24 billion online documents from 80 different countries, and annual revenues of $1 billion. As on other sites, the documents available online are those marshaled by genealogists, which is to say primarily nominative sources from civil registries, military records, and immigration records such as passenger lists for ships, passport applications, naturalization files, censuses, birth certificates, death certificates, marriage certificates, professional directories, and draft registration cards from the world wars.

Thanks to the indexing of these documents disseminated across the globe, keyword searches can find individuals by last name, first name, and geographical location. Ancestry offers more search criteria than its competitors and partners, including searches with no family name but rather a simple keyword such as trade, street name, ship name, nationality, “ethnic” identification, religion, etc. The site also offers searches for “events” such as a birth, marriage, death, or departure from a port or city. It also has a relatively effective functionality that spontaneously proposes individuals with a family relationship to the person being searched. The results are presented in two forms: a simple list of entries and classification by category, which distinguishes between documents from civil registries, censuses, immigration records, trips, and military archives. Finally, these results can be filtered by period and geographical location.

Screenshot of a results page from Ancestry © all rights reserved
Screenshot of a page from JewishGen © all rights reserved

Some sites are more specialized, such as JewishGen, a non-profit organization founded in 1987, and affiliated since 2003 with the Museum of Jewish Heritage in New York. When it was created, the site intended to be an international resource for Jewish genealogy. It was initially an email distribution list and online forum, before becoming an actual website in 1995. In 2008, JewishGen established a partnership with Ancestry, which helped improve its technical performance, and provided it with stable income. In return, Ancestry offered its subscribers access to the genealogical resources collected by JewishGen, which nevertheless remains a free tool. The site functions primarily thanks to volunteers, and includes a few million documents from over 850 collections worldwide that specifically concern Jewish families. It consists of multiple separate databases (such as The JewishGen Family Finder, The JewishGen Online Worldwide Burial Registry, and The JewishGen Holocaust Database), but also allows search requests across all of these resources. It is also possible to limit searches to a specific country.

The Limits and Biases of These Tools

These websites propose extremely rich offerings, in which both amateur and experienced genealogists can quickly be overwhelmed. It is important to note that a number of them have signed agreements with one another, and hence at times propose redundant offerings. For example, Ancestry and FamilySearch announced a partnership in 2013 to digitize and index over a billion documents from across the globe. These documents are still freely available on FamilySearch, and are also accessible via a subscription to Ancestry, broadening its offerings. That same year MyHeritage allowed FamilySearch to use its technological advances, thereby expanding its collections. In 2014, MyHeritage established a partnership with BillionGraves to digitize and document all of the world’s tombs and cemeteries. These examples show the difficulty of clearly delimiting collections based on provenance, as a researcher habitually does when frequenting physical archival sites. It is therefore important to underscore the source for documents found using these websites.

Screenshot of a page from FamilySearch referring the reader to the website BillionGraves © all rights reserved

Despite the advantages offered by these tools, they have numerous limitations that should be kept in mind. First, they are designed to establish one’s family history, and hence are exclusively oriented toward certain types of sources traditionally used by genealogists. It would be wrong to think that these databases are sufficient on their own, for like any other source they offer a partial view of reality, in this case through a genealogical prism.

Another potential pitfall is the sheer quantity of digitized documents can give an illusion of exhaustiveness that is far from being real. Some documents are poorly indexed, and hence “unfindable” by keyword searches; some collections are not entirely digitized, and for that matter it is difficult to follow the logic used in selecting which “batches” are made available online. Finally, even if they claim to offer a global view, most sites remain centered on specific geographical areas. Ancestry, for instance, offers documents from over 80 different countries, although digitizations primarily concern the United States, and some parts of the world are genuine blind spots, especially Asia and Africa. The logic of digitization remains guided by economic considerations, as demonstrated by growing partnerships with Latin American archives in an effort to attract Hispanic clientele in the United States.

Process and Prospects for Research

Passenger list with the name Elka Peretz © New York, Passenger and Crew Lists (including Castle Garden and Ellis Island), 1820-1957 [database on-line]. Provo, UT, USA: Operations, Inc., 2011

Despite their biases, these websites offer invaluable resources for both genealogists and historians. With respect to the Lubartworld project, which aims to reconstitute the worldwide journeys of families from the same city, it is possible to search with the keyword “Lubartów,” and thereby access a highly diverse range of documents, in terms of both their nature and geographical origin. Let us consider the example of Elka Peretz: she appears in databases containing passenger lists bound for New York, in addition to US censuses, naturalization files, and social security records. When grouping these documents together, we learn that she was born on May 16, 1904 in Lubartów, and that she arrived in New York on August 29, 1934 from the Baltic Sea port of Gdynia. Her naturalization application indicates that she was naturalized as an American citizen in 1937. The 1940 US census reveals that she lived in the Bronx neighborhood of New York.

This initial search can be developed further through information contained in the collected documents. For example, her naturalization file mentions that she married Julius Peretz in Lubartów on November 7, 1933. A search using his last name reveals that he was born in Lubartów in 1894, and arrived in the United States in 1921, where he was naturalized in 1927. Some documents only appear in searches using the keyword “Lubartów.” There are multiple reasons for this: a misspelled name that soundex algorithms could not connect using consonant sounds;[6]A soundex is a phonetic algorithm that indexes names based on their pronunciation. Names with the … Continue reading an erroneous or missing indexing for the place of birth; or missing information in the original document.

Naturalization application form for Elka Peretz © New York, U.S., State and Federal Naturalization Records, 1794-1943 [database on-line]. Provo, UT, USA: Operations, Inc., 2013

Through multiple searches on a number of databases, and the supplemental information gradually gathered, an outline of the Peretz family’s journey between Poland and the United States emerges. The resources offered by genealogy websites are not sufficient on their own to fully reconstitute family itineraries, but they offer the easiest point of departure—thanks to document indexing and keyword searches—for pursuing inquiries in national and local archival centers. For example, most countries conserve naturalization or immigration files. Some associations or organizations also generated substantial archival collections, such as the International Refugee Organization, whose files are conserved at the French National Archives in Pierrefitte, and the archives of the International Refugee Organization (ITS) in Bad Arolsen, Germany. Finally, local archives also represent a substantial mine of information. In the case of inhabitants from Lubartów, the information gathered from genealogical databases can be compared with the that contained in the 1932 population register produced by the town.


Genealogy databases offer dizzying possibilities, but it is important to keep their limitations in mind, as they are tools designed for a very specific purpose that is not necessarily that of historical research. The information they provide can be illuminated by other sources, including local, national, and private archives. It is only by combining them that we can hope to particularly reconstruct family itineraries in all their complexity. In addition to helping reconstitute the migratory trajectories leaving from Lubartów and spreading across the globe, these databases can reveal the logic behind the mobility of these individuals and families, namely by studying their rhythms and temporalities on all spatial and temporal scales. They also analyze the development and functioning of social and economic migration networks through the circulation of information, money, and individuals serving as trailblazers, who subsequently provided a foothold for continued migration.