The history of zombies in horror cinema can be divided into two eras. There’s the period before Night of the Living Dead, in which the idea of the walking dead largely hinged on concepts appropriated from Haitian culture, with the deceased rising and taking actions under the direction of a magician like in White Zombie or Plague of the Zombies. Then there’s the period after Night of the Living Dead, when the concept was decoupled from its folkloric origins in favour of the newly-minted folklore of the zombie apocalypse.
Romero’s Dead movies effectively form three trilogies; there’s the first three which are the truly seminal work, then there’s the second three from the 2000s – Land of the Dead, Diary of the Dead, and Survival of the Dead, which came about in a time when Romero had become so typecast as a director that he couldn’t get a non-zombie project off the ground and he leaned into it, thanks in part to the revival of the genre in the wake of 28 Days Later, Shaun of the Dead, and Zack Snyder’s Dawn of the Dead remake. Though Land of the Dead was pretty good and the other two had their moment, it’s safe to say the second trilogy is not what Romero’s legacy is largely built on – for that, you need to dig a bit deeper.
Night of the Living Dead
Night of the Living Dead more or less entirely changed the way zombies were depicted in cinema forever after, presenting a narrative which is simple enough to become archetypal but nuanced enough that there’s depth to it beyond the basic survival horror premise. Unfortunately, it’s been quite badly treated over the years in terms of home media releases or downloads as an upshot of a blunder by the original distributor causing the film to enter the public domain in the US.