The reconstruction of the past, the care and the conservation of historical sources are only a recent practice in Arcetri. As a matter of fact, in 1958, the then director Guglielmo Righini, in order to "get rid of the past" deposited old instruments, books and records belonging to the Observatory with the Institute and Museum of the History of Science in Firenze. A complex path to recover and acquire these items then became necessary to reconstruct the historical archives.
During the 90's, following restoration works in the Library and other Observatory rooms, some folders containing records of various types (letters, drafts of articles, manuscripts, observation records) were found, and it was soon clear that the documents were important. This discovery raised strong awareness of the importance of safeguarding and valorizingthe historical memory, and led the Observatory director to begin the recovery and reconstruction of the historical archives. At the time these consisted of 31 folders, which included a part relating to the recent history of the institution, and another part concerning the works of Antonio Abetti and Giorgio Abetti, Observatory directors from 1894 to 1922 and from 1922 to 1953, respectively. The latter section contains some very interesting materials, the letters by George Ellery Hale to Giorgio Abetti for the construction of the solar tower and the records related to the observations. In the following months other records, of an administrative and accounting nature, were found in Arcetri.
In 1998, the Sovrintendenza Archivistica for Tuscany inspected the archival documents to evaluate their extent and considered them to be of remarkable historical value.
In 2003, the collaboration of the Institute and Museum of the History of Science (IMSS), now known as the Museo Galileo, allowed the retrieval of what was initially thought to be the entire body of the Observatory's old documents, In particular, a wealth of records belonging to the Abetti fond and folders containing correspondences concerning the De Filippi expedition to Karakorum in 1913-1914 were found. In addition, in the spring of 2007, the IMSS found further Observatory records and, after ascertaining to their authenticity, they were added to the archives. The documents consisted of a total of 60 pieces among envelopes, registers and parcels and included the oldest observation records, dating back to the time when the Observatory site was in the tower of Palazzo Torrigiani, on Romana street.
A further acquisition took place in 2006, when records relating to Giovanni Battista Donati were purchased from an American antique dealer. These letters covered the period 1854-1872 and were sent to Donati by Italian and foreign distinguished scientists such as Le Verrier, Secchi, Tacchini, Schiaparelli and Delaunay, etc. The body of letters confirms the network of international relationships woven by G. B. Donati which was also aimed at surveying single astronomical events. For instance, the vast body of documents relating to the Aurora Borealis of 1872 witnesses the contacts he had made all over the world.
Lastly, a valuable finding was made inside a folder held at the Observatory, it contained about 130 letters by P. Angelo Secchi to Pietro Tacchini (1865-1877), donated to Giorgio Abetti in 1939 by Tacchini's nephew.