June 7, 1861 (Friday). "The Army Must Have No Enemies in the Rear"

General George Henry Thomas

                                    HEADQUARTER DEPARTMENT OF PENNSYLVANIA

                                                                        Chambersburg, Pa., June 7, 1861

Col. George H. Thomas, U.S.A.,

            Second Cavalry, Comdg. First Brigade, Greencastle, Pa.:

   COLONEL: The commanding general does not wish to make any movement forward tending to permanent occupation till he is prepared with all his force to sustain the advance.  He wishes every precaution taken against precipitate action and nursing ill-feeling, both by political discussions and improper conduct of the men.  The Army must have no enemies in the rear.  On your prudence and judgment he relies to sustain the present status.

    Appeals my be made to cross into Virginia to protect Union people under assurance that a small force only is required to present itself for disunion to hide its head and loyal people to flock to your banners.  They must not be heeded.  If, however, inroads are made into Maryland within your reach, the commanding general desires you to meet the invaders with a force which will ride down all opposition, and in all cases to return to your present camp.  When practicable, the surprise of armed parties will be effected.  Brigadier-General Williams will be immediately in your rear, and is directed to sustain you in all cases.

      I am, &c.

                                                                                    F. J. PORTER,

                                                                        Assistant Adjutant-General

Official Record, Series I, Vol. II, Page 670

A curious bit of correspondence, addressed to the man who would become “The Rock of Chickamauga”.  Thomas was a Virginian who remained loyal to the Union and began the war in command of a regular Army cavalry unit. Porter was A.A.G. to General Patterson, in command of the Department of Pennsylvania.  Patterson desired to move forward to Hagerstown, but General Scott held him back, desiring he advance no further than Greencastle, PA. (about 15 miles North).  It is not at all clear why Porter called the attention of Thomas to “..nursing ill-feeling, both by political discussions and improper conduct of the men.”  However, Porter was firmly in the McClellan camp, which wished to limit the scope of the war and minimize impacts on civilians.  There are no letters in the O.R. by Thomas to Patterson or Porter which might answer the question.