Yes, they all appear to be union troops. I’ve noticed that the dailmail.com has lots of features on Civil War topics - perhaps they’ll present some confederate photos.
To be honest the Rebs couldn’t afford to have many pictures taken. Only the Officers had portraits and the common soldier is always a corpse taken by sicko Brady et al.
I'm currently into an eye-opening book about southern US slavery. The biographic main character is a slave named Robert Smalls. The book title is "Yearning to breathe free" by Andrew Billingsley and ... it's a terrific read.