I seem to leave the area every time this comes up in the movie:
What did he do during the CW that was so bad
He and York seem to be sharing command when Thursday arrives although he is the senior man, and some kind of contemporary of Thursdays
In a world where a carpenter can be resurrected,anything is possible
*****POSSIBLE SPOILERS******
You didn't miss it by going for a snack, foster. They never explicitly said what. However, during the climaxic attack, when Col Thursday rejoins the doomed men, Collingwood, while reviving him with a drink from a canteen says something like "I guess it was you who were late this time, Owen." Which I took to mean that Thursday had accused his subordinate Collingwood of being late bringing up his men in a Civil War battle, and had perhaps, fairly or unfairly entered a reprimand in Collingwood's record because of it.
He maketh His sun to rise on the evil and on the good... St. Matthew 5:45
I'm just watching a showing of the film on TV now. I've always liked the way the back story that these two men share is never made explicit.
From Thursday's entrance at the dance, where Collingwood refers to him as 'Owen' we realise they know each other. Then at officer's call '...it's nothing personal...' as Collingwood is replaced as regimental adjutant, and after the offer of a drink '...it's a little early, even for me...'.
Then, at dinner with the Collingwoods, York, Lt. O'Rourke and Phil, discussing his re-assignment;
'...you know the army's opinion of me...'
'...and you now our opinion of you...' '...and you know how the men feel about you...'
'...gentlemen, my compliments...'.
As a sentimental fool, I like to think that whatever his 'crime' (late to battle, alcohol, a bad decision*) over the time he has spent (essentially exiled) at Fort Apache he has redeemed himself, at least in the eyes of those who serve with and under him.
*There's also Mrs Collingwood's '...he's not a coward...' as she receives news of his reassignment, but elects not to have him told as he rides out of the fort with his troop, knowing full well what may happen.
Acr ukl,
You did a great job of summing up all the clues to Collingwood's past, most likely his service during the Civil War. I, too, like the way his past is left to our imaginations. As you say, he has redeemed himself in the eyes of the rank and file, if he ever lost that respect, but, from Thursday's treatment of him, his reputation is still in the minds of the upper brass.
That, to me, at least, shows that Emily Collingwood is a true army wife. She could have called her husband back and saved him from death, as the other wives wanted her to do, but she knew that this engagement was his chance to redeem himself in the eyes of the army as a whole, and, even if it meant his death, she would not call him back. If he had left the column and come back to the fort and survived the Indian attack, the cloud over him would have been greater. She would not condemn him to that, and, by the expressions on the faces of the other wives, they knew exactly why she refused to call him back. It was a moment that taught Phil just what it meant to be married to the army.
Sorry to have rambled so, but this is one of my favorite movies.
Spin
I also like the fact that the audience never sees Mrs. Collingwood again after the scene on the roof. We can imagine for ourselves what emotions she had to deal with.
"We're fighting for this woman's honor, which is more than she ever did."