Eastern cities linked to the oil fields by rail and boat boomed also. The export trade from Philadelphia, New York, and Baltimore became so important that Standard and other companies located refineries in those cities. As early as 1866 the value of petroleum products exported to Europe provided a trade balance sufficient to pay the interest on U.S. bonds held abroad.
When the Civil War interrupted the regular flow of kerosene and other petroleum products to western states, pressure increased to find a better method of utilizing oil found in such states as California. But Standard exhibited little interest in the oil industry on the West Coast before 1900. In that year it purchased the Pacific Coast Oil Company and in 1906 incorporated all its western operations into Pacific Oil, now Chevron.