The original concept of the zombie started with the Haitian Voodoo culture where a priest or Bokor would administer a powder referred to as coup padre
to an individual and he would start his transformation into zombiism. Their heart rate would slow down and their breathing would become shallow so they would have the appearance of being dead. Their soul would become possessed by the Bokor and the zombie would do nothing except perform the will of the Bokor.
There have been many movies based on these zombies from the 1930s all the way to the 1960s. So how did we get from these mindless drones to the zombies of today? Que Mr. George A. Romero.
Romero's 1968 cult classic, Night of the Living Dead
, brought the zombie from a mindless vegetable under the control of some spiritual being to the flesh craving undead horde that everyone knows and loves. Just about every book, movie, and tv show that has had anything to do with zombies since the late 60s has been based on Romero's version of the zombie.