The purpose of the article is to reveal the idea of the emergence and evolution of the FRUS publication as the gold standard of official documentary history, to analyze the main periods of the collection's development, focus on the legislative basis for the publication of the series and the problems of understanding the FRUS series as an example of the transparency of the American government. Analyzing the scientific work on the topic of the study, the author draws attention to two aspects: the lack of interest in this collection in the Ukrainian scientific community and the rather limited interest among the world scientific community. The research methodology is based on the principles of historicism, objectivity, a systematic approach, and relevant general scientific methods such as problem-chronological and information analysis. The scientific novelty is determined by showing the evolution of the collection, its functional orientation, and the proposed periodization of the publication's development. Conclusions: The publication of the collection began in 1861 and was viewed by Congress not only as a means of informing the public but also as a tool to control the executive branch. No clear criteria for publishing or removing materials were made public, although there was a consensus on which materials should not be published, namely those “that would be detrimental to the public good”. The publications of the period 1861-1905 did not take into account the fact of inconvenience to foreign governments, American diplomats, or US presidents. It is emphasized that the publications of the period 1920-1945 underwent profound changes in purpose, production, design procedures, and target audience. This period is associated with the appearance of the first official order that provided for mandatory historical “objectivity” and served as a charter for the series (with minor changes) until 1991. It is pointed out that the content of the collection and the speed of its appearance were seen as direct evidence of the US government's adherence to the policy of transparency and accountability. As a result, between 1920 and 1945, the State Department released 56 volumes, covering the years between 1913 and 1930. It is noted that gradually the balance between transparency and national security became increasingly difficult. The FRUS series has been and remains a vital resource for the public, academia, political scientists, and others. After the end of World War II, the State Department redefined the transparency paradigms of the 20th century. From the 1950s to the 1980s, the imperatives of the Cold War affected the timeliness of publication, as well as the decision-making process for declassifying U.S. government documents. At the beginning of the Cold War, the FRUS series was 15 years behind on average; by the 1980s, this gap had doubled to about 30 years. The volumes were also subjected to greater scrutiny by the U.S. government before being released. This was partly a result of expanding bureaucratic frameworks and partly a consequence of the Cold War. The publications of the second half of the twentieth and early twenty-first centuries moved away from the functional component of the nineteenth century and instead became a means of a certain historical transparency. The FRUS publications will allow us to analyze not only the evolution of US diplomatic skill but also the policy of openness as a key element of democratic development.