Series contains mostly incoming personal and professional correspondence, both typed and handwritten letters and postcards, sent to Elsberg from friends, literary associates, and Bogg subscribers. Items that came with the letters, including photographs and newspaper clippings, remain with the correspondence.

Series also contains correspondence with Elsberg regarding submissions to and works included in Bogg, works published through Bogg Publications, Bogg subscriptions, small press exchanges, and reviews and responses to Elsberg's work and works published through Bogg Publications.

The correspondence arrived at Spencer Research Library in rough chronological order and has been maintained in that order. Spencer Library staff separated the correspondence by year to make it easier to find material, and some pieces were rearranged in order to match the general chronological order of the series.