It was indeed a tradition.
Costumes?
Store bought costumes were available, but we kind of felt sorry for the kids who ended up with them.They were cheesy looking things made of thin fabric, plastic, or even crepe paper, which disintegrated if it rained. In most households around here though,Moms and Dads and the kids would brainstorm and find some stuff around the house to make a costume.
ie;boxes painted and an empty ice cream tub (scrounged from the local variety store) painted silver, and you were a robot. or...Mom's old cocktail dress and a lace table cloth, a paper fan, and you become.a Spanish Senorita. If no ideas at all at home, the traditional bed sheet with eye holes for a ghost, or coming as a clown or hobo were common costumes.
Some Moms even had the time to sew up a costume. There were patterns for them available and sewing machines in most homes.
Treats?
There were candy apples(much sought after),even rumors of caramel apples(but I never obtained one), wrapped candies, peanuts, popcorn balls, apples, licorice(if you were lucky) and gum.
Tricks? Not many of those played. Did see a toilet papered tree once.