I've done a little (very little) research on Ritchie before. I read all I could find in the ORs. Below is the text of a message I posted last spring. I believe Shirley's Ford is the Sept 1862 event you mention that got him temporarily removed. I sure would like to find a biography for him or at least more info on his military service.
Col. John Ritchie, 2nd IHG, was arrested after his little expedition to Shirley's Ford MO but he was apparently reinstated.
In April 1863, Lt.Col. Schaurte takes command of the 2nd IHG at Ft Gibson and says Ritchie is on detached service in Kansas.
In March 1864, Blunt/Curtis put Ritchie back in command of the 2nd IHG and send him to Mackey's Salt Works (where the Ft Smith-Ft Gibson Road crosses the Illinois River about 10 miles from the mouth).
In Oct. 1864, Ritchie is 'volunteer aide-de-camp' to Curtis in Kansas and is arrested by Maj Gen Pleasonton but released at Curtis' request.
Where was Ritchie in between these dates? Is anyone aware of any biographical information on him? Who were his political connections that kept him from being dismissed from the army?