Our people, though shocked and very much disappointed, are in better tone and temper than I feared they would be. The press had wrought the public mind to high expectation by predicting certain success, which all wished to believe. I have not been confident, though I had hopes. Hooker has not been tried in so high and responsible a position. He is gallant and efficient as commander of a division, but I am apprehensive not equal to that of General-in-Chief. I have not, however, sufficient data for a correct and intelligent opinion. A portion of his plan seems to have been well devised, and his crossing the river well executed. It is not clear that his position at Chancellorsville was well selected, and he seems not to have been prepared for Stonewall Jackson's favorite plan of attack. Our men fought well, though it seems not one half of them were engaged. I do not learn why Stoneman was left, or why Hooker recrossed the river without hearing from him, or why he recrossed at all.
It is not explained why Sedgwick and his command were left single-handed to fight against greatly superior numbers — the whole army of Lee in fact — on Monday, when Hooker with all his forces was unemployed only three miles distant. There are, indeed, many matters which require explanation.
SOURCE: Gideon Welles, Diary of Gideon Welles, Secretary of the Navy Under Lincoln and Johnson, Vol. 1: 1861 – March 30, 1864, p. 294-5