Zombies are the monsters of the 21st century, and America's major contribution to horror. What set off zombie fever? All roads lead to George Romero, who made zombies a metaphor for social ills.
Slasher films killed in the '80s, but their violence, perceived misogyny, and endless sequels almost ended the genre. Supernatural killers Chucky and Freddy saved them from extinction.
Slashers got sophisticated in the '90s, evolving from Freddy Kreuger to Candyman to the terrifying Hannibal Lector. The 2000s brought "torture porn" - a response to post-9/11 panic.