The materials that comprise the Kansas City, Watkins & Gulf Railway Company series are a surprisingly complete history of the creation and construction of this railroad from Lake Charles to Alexandria, Louisiana. J. B. Watkins personally financed and built the line through the sale of railway bonds offered, primarily to prior investors in the land mortgage company. On completion of the line, he sold the entire operation to the railway company.

The records of the Kansas City, Watkins & Gulf Railway Company were saved only by Watkins' decision to transfer company bookkeeping and accounting functions to the Lawrence office. The line was constructed between 1890 and 1892, with proposed extensions northward to Natchez and Shreveport, and south to the gulf coast being considered as late as 1896. With the collapse of the land mortgage business, the fortunes of the railway company were adversely affected and the extensions were never built. Reorganization of the line was ordered in 1896 with receivership appointed in 1898.

Correspondence in this series features the regular reports of the chief engineer, land purchasing and right-of-way agents, superintendent, and general managers of the line. Materials also include the records of railway bonds sold, statements of contractors and suppliers involved in construction, and platting of townsite companies along the line. There are also financial statements compiled by the London office concerning the sale and disposition of railway company bonds.

Information is also available on the construction and operation of the Lake Charles Inter-Urban Rail Line. Of particular interest is a group of materials created by the Immigration Department of the Kansas City, Watkins & Gulf Railway Company. A Louisiana Exhibition Car was outfitted by this department and travelled the United States, advertising southwest Louisiana and encouraging immigration to the area. The car was supported by immigration agents and publicity materials that accompanied the car in its travels.

The materials of this series document the creation and construction of this railway from start to finish. The line was instrumental in Watkins' plans for the development of the region into a major agricultural and commercial center of the United States.