Using other people's money is, as Joseph Schumpeter pointed out, what entrepreneurs do. "...risk bearing is no part of the entrepreneurial function. It is the capitalist who bears the risk. The entrepreneur does so only to the extent to which, besides being an entrepreneur, he is also a capitalist, but qua entrepreneur he loses other people's money."
I take this account from Harold Holzer, Lincoln at Cooper Union: The Speech That Made Abraham Lincoln President (New York: Simon & Schuster, 2004), 60-65.
For the system before the Civil War see, James E. Vance, Jr., The North American Railroad: Its Origin, Evolution, and Geography (Baltimore: Johns Hopkins University Press, c. 1995), 1-124.
This account and what follows is drawn largely from Samuel Richey Kamm, "The Civil War Career of Thomas A. Scott," (Ph.D. Dissertation, University of Pennsylvania, 1940).
See also, Robert C. Angevine, The Railroad and the State: War, Politics, and Technology in Nineteenth-Century America (Stanford, CA, Stanford University Press, 2004), 133-34.
Kamm, "The Civil War Career of Thomas A. Scott," 3-4 11-18.
Douglas E. Bowers, "Logrolling to Corruption: The Development of Lobbying in Pennsylvania, 1815-1861," Journal of the Early Republic 4 (Winter, 1983), 469-70.