It has been the intention of the writer to present a brief history of the Baltimore and Ohio Railroad from its inception in 1826 until its completion to Wheeling in January, 1853. The monograph has been designed as a study in the economics of transportation, and stress has been laid upon the influence of the railroad in the development of the industryand commerce of the city of Baltimore, and of the agricultural, mineral and manufacturing resources of the state of Maryland. The Baltimore and Ohio having been the first great through-route railroad projected in America, has naturally an important place in the regard of the student of transportation. The beginnings of some of the present difficult railroad problems appear in the history of this road, and these have not only been treated incidentally as they appeared in connection with the legislative, financial and mechanical history of the railroad, but have been summarized in the final chapter.