All the reference of caps and hats may be that officers participated (in the tossing in air or dipping of water), there is no doubt that the prescribed uniform for enlisted was to be uniformed in caps. Individuals would try to get away with what they felt more comfortable, particularly when certain commanders were absent, either by wounding or other. I believe the intent is clear via the aforementioned missives and there is an order from Hancock, that I have not had the time to find. (fiscal year closes next month and the natives are restless)
Absolutely concur these order demonstrate that the official "uniform" of the units was to include
only the forage cap among the troops in question, which seemed to be common among Union troops, and especially in the Army of the Potomac. That's what I've previously understood given the March 21, 1863 Gen. Hooker as the commanding general ordered the corps badges on caps specifically.
And that off duty or on the march etc. some men didn't concern themselves about the uniform, and chose to wear hats instead, and maybe for duty purposes when they were allowed...
Certainly the majority in the AoP felt constrained to forego a hat. The veterans of the 1st Maine Heavy Artillery recalled the forage caps only redeeming features, so far as the soldiers were concerned:
As the September, 1864 order of General Miles notes, some men of the 2nd Corps were wearing hats "allowed" during the recent campaign. So much so as to issue a general order against it. Waud sketch, 2nd Corps men on the Brock Road, May, 1864:
I'm sure in the immediate aftermath of the September order the 2nd Corps men showed up for duty with forage caps to avoid punishment. But by Feb., '65 notice numerous hats yet worn in the camps and threatened destruction of their hats where the uniform forage cap was required.
2nd Corps infantry at Armstrong's Mill Oct. 27, 1864:
Among the 2nd Corps, at the time these orders were issued relative to getting the troops back into a uniform standard, a large number of recruits had been received. By mid-October a large part of the personnel, and more arriving. General Humphrey's noted these recruits were not previously instructed or disciplined.
Before the end of 1864, the Corps was taken from the lines for rest and drill...in a position "in reserve" near the front:
The day after the Feb. 4, '65 order to destroy any felt hats worn in lieu of the caps, the corps went back into action near Hatcher's Run on Feb. 5-6. Gen. Humphrey's was pleased with their actions...
In the same 1865 period as the 2nd Corps orders quoted, there are some similar references from the 6th Corps. From February 28, 1865 ordering the men in their winter camp situation to wear their caps, in lieu of their many hats and regulation shoes instead of their boots in the mud, emanating from Gen. Seymour. As the veterans of one regiment noted:
No doubt these orders were obeyed. Yet by April 9, as the Appomattox campaign concluded, these orders were renewed again, because some fellows were again wearing hats. And where General Miles had threatened to destroy any hats in the ranks of his command, Seymour evidently limited the destruction to the light colored ones particularly:
A veteran of the 5th Wisconsin, with the Sixth Corps' first division, noted later they drew new caps prior to the Grand Review at Washington at the end of May.
At the Grand Review of the army of May 23, 1865, it was noted in several accounts, the Army of the Potomac troops appeared to great advantage, almost universally in their uniform forage caps. Chaps of the 7th Rhode Island recalled their staging for the grand review...
Here's General Humphrey's of the 2nd Corps with his staff, in that parade wearing hats.
No doubt the 2nd Corps troops parading behind were in the army's uniform, in forage caps like most of the Army of the Potomac.
Given it was a grand review, etc. it would not have been appropriate for the soldiers to have worn other than the required forage caps.
The next day many of Sherman's troops were there paraded wearing hats...
Like these 20th Corps fellows:
One of Sherman's troops, however, mentions his regiment drew forage caps to wear the day before the parade...though the balance of their clothing was somewhat worn and shabby, and determined to make a good showing...
Post-war, the regular troops continued to wear the uniform hat as a campaign hat or slouch hats, etc. in the field. For example in the Modoc War of 1872-73.
Even the Modoc Army scouts seemed to like them...
That same year the US Army revised its uniform regulations, to include a hat specifically for "marches or campaigns" while common garrison wear included dress caps or helmets, and forage caps.
Bringing the