Perkins to Forbes, Sept. 24, 1879, 3 F 3.23.3, J. M. Forbes, In-letters, private from C. E. Perkins, CB&Q.

A Letter to Hon. S. M. Cullom from Charles E. Perkins, Sept. 21, 1885, 3, P4.12, Chicago, Burlington & Quincy Statement, Charles Francis Adams, May 24, 1887, PRC, 2:605-6.