I had always intended to divide time with my natural successor, General P. H. Sheridan, and early, notified him that I should about the year 1884 retire from the command of the army, leaving him about an equal period of time for the highest office in the army.  It so happened that Congress had meantime by successive “enactments” cut down the army to twenty-five thousand men, the usual strength of a corps d’armee, the legitimate command of a lieutenant-general.  Up to 1882 officers not disabled by wounds or sickness could only avail themselves of the privileges of retirement on application, after thirty years of service, at sixty-two years of age; but on the 30th of June, 1882, a bill was passed which, by operation of the law itself, compulsorily retired all army officers, regardless of rank, at the age of sixty-four years.  At the time this law was debated in Congress, I was consulted by Senators and others in the most friendly manner, representing that, if I wanted it, an exception could justly and easily be made in favor of the general and lieutenant-general, whose commissions expired with their lives; but I invariably replied that I did not ask or expect an exception in my case, because no one could know or realize when his own mental and physical powers began to decline.  I remembered well the experience of Gil Blas with the Bishop of Granada, and favored the passage of the law fixing a positive period for retirement, to obviate in the future special cases of injustice such as I had seen in the recent past.  The law was passed, and every officer then knew the very day on which he must retire, and could make his preparations accordingly.  In my own case the law was liberal in the extreme, being “without reduction in his current pay and allowances.”

I would be sixty-four years old on the 8th of February, 1884, a date inconvenient to move, and not suited to other incidents; so I resolved to retire on the 1st day of November, 1883, to resume my former home at St. Louis, and give my successor ample time to meet the incoming Congress, But, preliminary thereto, I concluded to make one more tour of the continent, going out to the Pacific by the Northern route, and returning by that of the thirty-fifth parallel.  This we accomplished, beginning at Buffalo, June 21st, and ending at St. Louis, Missouri, September 30, 1883, a full and most excellent account of which can be found in Colonel Tidball’s “Diary,” which forms part of the report of the General of the Army for the year 1883.

Before retiring also, as was my duty, I desired that my aides-de-camp who had been so faithful and true to me should not suffer by my act.  All were to retain the rank of colonels of cavalry till the last day, February 8, 1884; but meantime each secured places, as follows: 

Colonel O. M. Poe was lieutenant-colonel of the Engineer Corps United States Army, and was by his own choice assigned to Detroit in charge of the engineering works on the Upper Lakes, which duty was most congenial to him.