Letter written October 26, 1866 by Leavenworth, Kansas businessman H. D. Mackay, denouncing the administration of U. S. President Andrew Johnson in the nation's period of post-Civil War Reconstruction. The envelope is addressed to L. E. Campbell but postmarked September 28. Mackay's letter is to Lieutenant Lafayette Campbell, who later married a niece of Johnson's successor, Ulysses S. Grant.

The Minnis family papers are those of a longtime Kansas family. They focus on Marian N. (Freeman) Minnis and her son Frank B. Minnis Jr., who served for a number of years as a Leavenworth City Commissioner and, for a short time, as that city's mayor.