According to Starr, Jennison was court martialed and dishonorably discharged from the Union Army after various war crimes commited by his command while down in Arkansas. (An anonymous correspondent with the 15th bragged of how the 15th had implemented their own version of General Order No. 11.) It is interesting that there is no mention of this court martial in the Adjutant General's Report (originally published in 1867), and that the table of data for the 15th does not show an officer being dishonorably discharged.

Hmmm...it seems to me politics (was Jennison a state representative by then?)and the aggrandizement of the Kansas contribution (still trying to recovery from the "Jayhawker" notoriety?) could have been factors in what ended up in that report.