Von Knappe was accused of libeling the memory of Lincoln in his book on the history of the Wabash Valley. While I haven't completed my research on this yet, neither Tarbell nor RTL ever testified, and Von Knappe was acquitted. It wouldn't be out of the question to suspect that being a German at the time of World War I likely played a role in it as well.
Best
Rob
Just a note of correction. I said Von Knappe was acquitted, but according to some information I forgot I had, just a few days before his trial was to begin, Von Knappe pled guilty to "printing and distributing obscene literature.” He was fined $25 and court costs, a total of $34.50.
RW
Abraham Lincoln is the only man, dead or alive, with whom I could have spent five years without one hour of boredom.
--Ida M. Tarbell
I want the respect of intelligent men, but I will choose for myself the intelligent.