A young Kolthoff on vacation in the mountains, somewhere in Europe, ca. 1910s. Used with the permission of the University of Minnesota Department of Chemistry.

Izaak Kolthoff lecturing in Russia, 1958. Used with the permission of the University of Minnesota Department of Chemistry.

Izaak Kolthoff (left) with University of Minnesota President C. Peter Magrath at the dedication of Kolthoff Hall, 1972. Used with the permission of the University of Minnesota Department of Chemistry.

J. Edgar Hoover, director of the FBI during Hamm and Bremer kidnappings, in 1940. Hoover guided the FBI’s attempts to rid the US of “public enemies” like the Barker‒Karpis gang.