I suppose any mention of railroad strikes Twain may have made would have 
been in correspondence with Rogers.  Twain was back and forth between 
Europe and the US between May and July of 1894.  He wrote several 
letters to Rogers in that period.  I have just now discovered an edition 
of his letters on Abe Books and hopefully somewhere in this letters 
there will be some mention of Pullman and/or Eugene Debs.