Cary J. Mock, "Rainfall in the Garden of the United States Great Plains, 1870-79," Climatic Change 44 (2000): 191.
Mock, "Rainfall in the Garden," 184, 187-88.
As I have argued above, the Central Pacific and the Union Pacific both could make money as regional roads serving San Francisco and Omaha, and through connections Chicago, respectively, but as the subsidies they paid show, they could not make money as a transcontinental. In any case, given the corruption of the books, it is very hard to make any definitive case about either road.
The per capita figure is from Alexander Klein, "Personal Income of U.S. States: Estimates for the Period 1880-1910," Warwick Economic Research Papers, no. 916, Department of Economics, University of Warwick.
The estimate of Huntington's estate is from James Thorpe, Henry Edwards Huntington: A Biography.
Klein, "Personal Income of U.S. States: Estimates for the Period 1880-1910."
The estimate of Huntington's estate is from James Thorpe, Henry Edwards Huntington: A Biography (Berkeley: University of California Press, 1994), 157.