Always Potterheads

Slytherin in the Battle

Ok. So, ever I just want to clear something up!
Did Slytherin fight for Hogwarts in the Battle?
Because McGonegall told them ALL to evacuate, right? Unless I understood wrong, but I doubt it.
Being a Slytherin, it made me just a smidge angry.
Just because most "bad-guys" were in Slytherin doesn't mean all Slytherins are bad! It was such a discrimination and it was so unfair for the Slytherins who wanted to stay and fight to be told not to.
People say that most of them would've had to duel family members who were death eaters, but that's no excuse because anyone's family member could've become a death eater!
I also read somewhere that they returned for the final battle against Voldemort - the one in which he died. But I don't know...
Can someone please enlighten me?

Also, if anyone has any requests then drop a comment! I'm thinking of what I should do more of: Jokes? One-shots? Imagines? Rants? Common misconceptions? If you have any ideas then please comment! Your feedback means a lot.
Same as what I should do less of.