On May 26th, 1862 William F. Pulliam was arrested in St. Clair County and as stated in a letter to Col. Burbank that he was from Cass County, and wished to take the Oath. This is just speculation as I have not read the letter or have detailed knowledge of his arrest but I am going to assume he was arrested for Guerrilla activity which seemed to be a Pulliam forte. (Missouri Union Provost Marshal Papers: 1861-1866 Reel # F1388)
Of even more interest is George M. Pulliam son of Robert Overton Pulliam (born KY 1809, d. Boone Co., Mo. 1884) who was arrested on Dec. 20th, 1861 for allegedly burning bridges. His trial and General H. Halleck's General Order # announcing his execution can be found in the O.R's and a letter of July 29th, 1862 to General Halleck detailing his innocence in Railroad destruction can be found in the Missouri Provost Marshals papers in the Missouri State Archives. I noticed on here mention of the Wilhite family and James Wilhite's arrest at the same time, as well as Capt. Drury Pulliam's connection to James on Sid Jackman's Staff. George M. Pulliam's grandmother was Elizabeth Wilhite and his great grandmother Hannah Jackman was the aunt of Sid Jackman.
George had a brother Luther Pulliam, Capt. Drury had a brother Luther and their other cousins in Fayette, Nathan Simes Pulliam (b. 1814 Ky. d. 1872 Fayette, Howard, Mo.) had a son named Luther born in 1844. The family moved from VA-TN-KY-IL (St. Clair, Pike, Randolph)-MO (Boone, Howard, Saline). It seems the whole clan was of the same political mindset, and had not been removed from the deep south long enough to change their ideals.