Correspondence, circulars, and other papers relating to the earliest incarnation of CB&Q. Incorporated in 1849 as the Aurora Branch Railroad, the company renamed itself Chicago and Aurora Railroad Company in 1852, and then Chicago, Burlington and Quincy Railroad Company in 1855. Includes correspondence between CB&Q and Illinois Central officials regarding a variety of railroad matters, and also a list of Illinois Central employee regulations dated 1854, one of the earliest examples of personnel regulations. Materials in this record group are not limited to these early companies, and also overlap heavily with materials in Record Group 2.