Series I contains general correspondence between Jason Rogers and his enormous circle of professional colleagues. These letters from journalists, educators, advertisers, and politicians mostly relate to Rogers's various campaigns to improve standards in newspaper marketing. One folder features correspondence from Rogers's time at the Kansas City Journal-Post. This series also includes some family letters, mainly between Jason Rogers and his son, Walter. Most of the correspondence here was filed separately in the Rogers papers. There are many more letters filed chronologically throughout the collection in folders directly related to specific subjects. For instance, each of Rogers's advertising campaigns contains its own documents, clippings, and correspondence.