The series contains annual reports to the stockholders, state legislatures, or to courts during periods of trusteeship. The purpose of the reports was to inform stockholders of the financial status and well-being of the company. The reports list the Board members and officers as well as provide information on income and expenses, investments, and operating statistics. In addition, the reports contain a brief narrative summary of the company's activities for the year in question. Reports issued by the NHRR will sometimes contain information on subsidiary operations.
Some annual reports contain maps, while later versions include photographs.
The subsidiaries are arranged alphabetically by company name. Within each company, the reports are arranged chronologically. The series is composed of reports filed by the NHRR and its subsidiaries in compliance with ICC regulations. The reports contain essential financial, statistical, and operating information of a detailed nature. Included are expenses and income, investments, mileage data, fuel consumption, passenger statistics, employee information, and accidents.