At the outset, the 3000 families survey aimed at reconstructing genealogies of the original TRA families. To do so, it made use of vital registers. The survey was initiated 25 years ago by an historical demographer, Jacques Dupâquier. It had both practical and programmatic ambitions: to gain new insight into the history of the French population via a large-scale survey at the national level. The challenge was to escape from the monographic process (studies at the family or village level) by collecting all vital information on individuals whose surname begins with the letters “TRA” in France as a whole. This information, once retrieved, was to be combined (by matching the various vital records on a given individual) in order to trace family ancestries (some of the 3000 TRA families were –at least initially– selected on the basis that their ancestor was born between 1800 and 1820). This sample was designed to be representative of 1/1000th of the French population (which was one reason for choosing the letters TRA).
However, in practice, the demographic component of the survey grew relatively slowly, especially because of the huge volume of work to be done. Retrieval of archive data relied on an army of voluntary genealogists whose work had somehow to be organized and standardized. Data entry took much longer than expected so some types of data could not be recorded (for instance detailed information on marriages). Information for the 20th century was particularly difficult to obtain as the sources were not yet in the archives and, as a consequence, registers were widely dispersed.
Finally, the two parts of the TRA survey –the demographic and the inheritance components– have followed diverging paths. Working with distinctive sources and methods, they have evolved quite differently. As a consequence, individuals from both samples are not necessarily identical and the two parts are quite independent of one another. This explains why only the inheritance part of the TRA survey is presented here.