Comprising in-coming letters, alphabetically arranged by surname of correspondent. It is not clear why this series is named thus as many of the letters predate 1954, some dating from as early as 1928. However, the bulk of the letters date from the late 1940s to the mid 1960s. See composite name index to the catalogue for names of individual correspondents. There is also an ms list of correspondents at the front of each file. Box 1 = files 1-7, A-J; Box 2 = files 8-16, K-Y and unidentified.