The years following the American Civil War saw the growth of a new profession—that of "drummer" or traveling salesman. The traveling salesman was often assigned a "territory" or quota of sales calls to make that necessitated traveling day and night by train when in the field. In order to meet the needs of traveling salesmen and other nighttime travelers, Chicago inventor George Pullman helped to invent the sleeping car, a railroad passenger car whose seats could be converted into sleeping bunks.