What was the difference between commissioned and non-commissioned officers during the civil war, and could someone still be an enlisted man and be a second or first lieutenant?

by SmutGoddess

I'm writing a book and I actually have a TON of questions about the Battle of Antietam and the Civil War in general. I also have a question about obtaining ID in this day and age for someone not from this time (yes, a one-way trip through time is involved from 1862 to 2015), but I'll probably have to wait for /r/askreddit to be back up for that. Thanks in advance for any help!

DBHT14

So at a bar but will come back to this. Also on Sunday we are doing a full Civil War AMA with multiple active flaired experts committed.