Thurman William Van Metre, Outline of the development of the internal commerce of the United States
“ The term "internal commerce," though in its fullest signification embracing every purchase, sale, and exchange of commodities between the individuals of a country together with the business of transmitting intelligence and of transporting persons and things from place to place, is here used primarily as applying to the interchanges of commodities among the various sections of the United States carried on over interior lines of transportation--the rivers, highways, canals, lakes and railroads. ”
