Unknown to T. R. Cornelius, May 10, 1862

Col. T. R. CORNELIUS, First Oregon Cavalry, Portland, Oreg.:

COLONEL: In obedience to instructions from the headquarters Department of the Pacific, you will take prompt measures to organize the men already enlisted in your regiment into six companies in accordance with existing regulations and orders from the Adjutant-General’s Office for the cavalry volunteer service. The headquarters of your regiment will be at Fort Walla Walla, Wash. Ter., and you will hold yourself in readiness to move to that post with such companies as have completed their organization. Companies not yet mustered into service with the minimum standard of seventy-six enlisted men will be so merged and consolidated as to comply with the formation in the aggregate of six companies to the required standard, and upon notification to these headquarters an officer of the Army will be assigned to muster them into service and complete company organization. It is required that early and frequent information be furnished these headquarters as to the movement of the troops under your command, specifying the strength of the companies, their officers, and where posted.

Very respectfully, your obedient servant,