Imagine this scenario: You are a soldier in WWI. There is a jerk in your unit named Plunkett who is both a coward and incompetent. He does things like open fire without permission, causing a rain of enemy shells that also killed three of your fellow soldiers. Plunkett also gets scared during missions and screams, alerting the Germans to his presence. Needless to say, he is not that popular in your unit and is about to get transferred out. But then your units chaplain, beloved to the troops, convinces your commanding officer that he'll turn around if you give him one more chance and he's okay with this. If you are that soldier, wouldn't it be time to check to see whether you are either dreaming or doing some kind of hallucinogenic drugs, or perhaps entered another dimension while crossing the Atlantic?
So yes, this is one of those stupid movies Hollywood started to make around the end of the thirties, when American pictures started to go downhill. This is kind of the old-fashioned film that people refer to when they refer to old movies in a negative way. The ostensible purpose is, I suppose, is to commemorate the real life priest, Father Duffy (Pat O'Brien), who was a hero in both the Spanish-American War and WWI, but is showing the guy having horrid judgment the way to do it? Plunkett (James Cagney) is a fictional character that the movie doesn't need, and it's absolutely unbelievable that anyone could tolerate his behavior that kills at least seven fellow officers. Would the US army or any other for that matter tolerate this? If Plunkett were in the IRA, he would either not be an Ireland or not be above ground!
Why are we even supposed to care about this anyway? There are lots of interesting stories, both real and fictional, to tell about WWI, but this is not one of them. In fact, I would venture to argue that in many ways this is a proto-typical WWII film, and would be one had the US not joined that conflict at the time the picture was made. From a historical standpoint, it's interesting that so many films of the 30's tried to show how terrible WWI was, this one seems to avoid most of the discussions of the suffering of the soldiers (aside from the ones who die because Plunkett's gaffs, of course) or the political ramifications of the conflict.
The Fighting 69th is a weird and confused film, and I can't think of any reason to see it. Unless you are writing a master's thesis on WWI or the films of James Cagney, of course.
The Fighting 69th (1940)