I bought a 3" pin oak and planted it last fall. Things were going great and come springtime the leaves all came out. It had many low branches which I pruned. Since I did that, the leaves have all died and it looks like the tree is dead. Is there anything I can do to revive it? I'd hate to have a tree death on my conscience.
It sounds like you've shocked your plant - pruning is normally done in the fall for this reason. I'd baby it and hope it recovers.
I have no clue about trees. Does "baby it" just mean water it? At this point I'd give it massages and umbrella drinks to bring it back.
Water it when the soil is dry to the depth of your first knuckle, keep it in part shade, a little teensy bit of fertilizer, and just basically pray that it comes back.
"Things were going great" Does that mean you saw it with leaves on it last autumn? What color were the leaves if there were any?