E.P. Alexander tells the story of German immigrant captured at Fredericksburg in December 1862 who was nearly killed because of the number of his regiment:
One amusing incident happened to me as we entered the town. Quite a few citizens of the place, from one cause or another, had remained in the city during the whole period of the battle, taking refuge in cellars when either we or the Federals shelled it. As I went in with the skirmish line, I saw a citizen coming with a musket & bayonet, marching in front of him a Federal soldier. The prisoner was a rather small Dutchman, in bran[ d], new uniform & with a most complete & extensive equipment of knapsack, haversack, canteen, overcoat, rubbercloth, tin cup, bags of ground coffee & sugar, & all sorts of little tricks I never saw before. And everything was that neat that it was plain the man was one of the old maid types, with a genius for making himself comfortable. And that was how he came to be a prisoner. His captor gave me the impression, but I don’t know how, of being a clerk in a drug store. “Where did you get this man?” said I, as he came near. “He slipped into my cellar last night & went to sleep there. All the rest of the Yankees went across the river during the night, & he never knew it. I found him still asleep there this morning & I just took him prisoner & marched him out to give him to you all.” “Very good,” I said, & turning to the prisoner I asked him, “To what regiment do you belong?” “One hundred forty fort Pensilvany,” said he, with a very Dutch accent. Immediately his captor levelled the bayonet on him, & actually yelled, “God **** you! Did not I tell you, if you said that again I’d bayonet you! You damned lying—” & he was apparently really about to give the fellow a taste of the steel when I stopped him. “Hold on! What’s the matter? What are you threatening the man for?” “Why, didn’t you hear what he said?” “He only answered my question. I asked his regiment & he was obliged to reply.” “But didn’t you hear what the son of a ***** said? That he said the hundred & forty-fourth Pa.? Don’t you see that it’s just a dam Yankee trick. That they’ve just left this fellow here on purpose to tell that lie, & try & demoralize our men by making them think there are 144 regiments in their army from Pa.?” “Pshaw,” said I.
“They’ve got over 200 from some states, but it isn’t half enough yet to whip this army. So don’t stick him but take him along to the line. Our boys would not care if he was in the 500th regiment.” So I sent him on & hope the prisoner made the trip safely, but I never heard more of either of them.
[Fighting for the Confederacy: The Personal Recollections of General Edward Porter Alexander (Civil War America) (p. 185). The University of North Carolina Press. Kindle Edition.]
As far as I know, there was no 144th Pa. at Fredericksburg.
