The papers consist primarily of correspondence to and from Hajo Holborn. Correspondents of note include Theodore Heuss, who served as the first President of the Federal Republic of Germany following the Second World War from 1949 to 1959; German historian Friedrich Meinecke; and pioneering electronic music composer, Werner Kaegi. Also included are writings by Holborn; a newspaper clipping; a copy of remarks delivered at a meeting of the Yale history department on the occasion of Holborn's death; and an essay about Holborn written by Dietrich Gerhard.