On the 12th of March, 1864, General Grant was assigned to the command of the armies of the United States, as general-in-chief.  He was already in Washington, whither he had gone to receive his commission as lieutenant-general.  Shortly after his arrival there, he commenced to rearrange the different commands in the army to suit the plans which he intended to enter upon in the spring, and out of this grew a change in my career.  Many jealousies and much ill-feeling, the outgrowth of former campaigns, existed among officers of high grade in the Army of the Potomac in the winter of 1864, and several general officers were to be sent elsewhere in consequence.  Among these, General Alfred Pleasonton was to be relieved from the command of the cavalry, General Grant having expressed to the President dissatisfaction that so little had hitherto been accomplished by that arm of the service, and I was selected as chief of the cavalry corps of the Army of the Potomac, receiving on the night of the 23d of March from General Thomas at Chattanooga the following telegram: 

“March 23, 1864. 
“Major-general Thomas, Chattanooga

“Lieutenant-General Grant directs that Major-General Sheridan immediately repair to Washington and report to the Adjutant-General of the Army.

" H. W. Halleck, Major-General, Chief-of-Staff.”

I was not informed of the purpose for which I was to proceed to Washington, but I conjectured that it meant a severing of my relations with the Second Division, Fourth Army Corps.  I at once set about obeying the order, and as but little preparation was necessary, I started for Chattanooga the next day, without taking any formal leave of the troops I had so long commanded.  I could not do it; the bond existing between them and me had grown to such depth of attachment that I feared to trust my emotions in any formal parting from a body of soldiers who, from our mutual devotion, had long before lost their official designation, and by general consent within and without the command were called “Sheridan’s Division.”  When I took the train at the station the whole command was collected on the hill-sides around to see me off.  They had assembled spontaneously, officers and men, and as the cars moved out for Chattanooga they waved me farewell with demonstrations of affection.

A parting from such friends was indeed to be regretted.  They had never given me any trouble, nor done anything that could bring aught but honor to themselves.  I had confidence in them, and I believe they had in me.  They were ever steady, whether in victory or in misfortune, and as I tried always to be with them, to put them into the hottest fire if good could be gained, or save them from unnecessary loss, as occasion required, they amply repaid all my care and anxiety, courageously and readily meeting all demands in every emergency that arose.