Col. John M. Harrell, Confederate Military History, a library of Confederate States Military History: Volume 10.2, Arkansas
Clement Anselm Evans, Ed.

[118] from Fort Scott crossed the Cherokee border, and though Stand Watie and Boudinot made a gallant fight, they were compelled to fall back behind the Arkansas river. The Pin Indians rose in rebellion, and committed horrid excesses, causing between 1,000 and 2,000 helpless Cherokees to flee across the line into Arkansas, where they were subsisted at government expense. In regard to his doings in this matter it was stated in General Hindman's report:

Looking forward to this invasion, I had, on May 31st, the day of taking command, ordered General Pike to advance his force to the Kansas border for the protection of the Indian country. He was then at Fort McCulloch, about 25 miles from the extreme south line of that country, fortifying in an open prairie, with the Red river just in his rear. The order reached him June 8th. Receiving no information that it had been obeyed, I repeated it on June 17th, directing him to move at once to or near Fort Gibson, in the Cherokee nation. . . . On July 8th, he being still at Fort McCulloch, I again ordered him forward, instructing him to go by the way of Fort Smith, assume command of the troops in northwestern Arkansas, in addition to his own. . . . On July 21st he had succeeded in getting as far as Boggy Depot, a distance of 25 miles. In the meantime he had forwarded his resignation as brigadier-general, and applied to me to relieve him from duty. . . . I forwarded his resignation to Richmond, with my approval, and at the same time relieved him from duty. On the receipt of my order to that effect he issued and distributed a printed circular, addressed to the Indians, and equally likely to reach the enemy, in which, under pretense of defending the Confederate government, he evidently sought to excite prejudice against it. . . . Col. D. H. Cooper, who was next in rank and had succeeded to the command, deemed it his duty to place General Pike in arrest, and so informed me. . . . I approved his action and ordered General Pike sent to Little Rock in custody. . . . After his resignation had been accepted, Mr. Pike appeared at Fort McCulloch, issued an order as brigadier-general commanding, and prevented the march of troops. . .I again ordered him taken in custody. . . .