Some kind of quick transportation across country was, consequently, an indispensable condition of the national organization of American industry and commerce.

The railroad not only supplied this need, but coming as it did pretty much at the beginning of our industrial development, it largely modified and determined the character thereof.
By considerably increasing the area within which the products of any one locality could be profitably sold, it worked naturally in favor of the concentration of a few large factories in peculiarly favorable locations; and this natural process was accelerated by the policy which the larger companies adopted in the making of their rates.

The rapid growth of big producing establishments was forced, because of the rebates granted to them by the railroads.

Without such rebates the large manufacturing corporation controlled by a few individuals might still have come into existence; but these individuals would have been neither as powerful as they now are, nor as opulent, nor as much subject to suspicion.
It is peculiarly desirable to understand, consequently, just how these rebates came to be granted.

It was, apparently, contrary to the interest of the railroad companies to cut their rates for the benefit of any one class of customers; and it was, also, an illegal practice, which had to be carried on by secret and underhand methods.