Compiled and prepared by approximately 20 historians and editors at the Office of the Historian in the US Department of State, the The Foreign Relations of the United States series is "the official documentary historical record of major US foreign policy decisions and significant diplomatic activity." The series initially began in 1861 and now comprises over 350 volumes, but more recent volumes have made increasing use of declassified records, Presidential tape recordings, and documents from a wider range of government agencies, "particularly those involved with intelligence activity and covert actions." A number of the most recently released volumes have also been made available in electronic form. Currently, users can read 21 volumes online in their entirety, featuring original documents from the Truman, Eisenhower, Kennedy, and Johnson Administrations. At the site, users can also read summaries of recently released volumes, look at press releases, and view the complete list of volumes from 1861 to present.