question regarding zombie history

I just watched White Zombie for the first time in well over seven or eight years and as a fan of the genre, I found it interesting that the zombies in the first ever film about them where actually put into a death like coma, buried, and then unburied, and then revived in a 'trance-like zombie state', controlled by the voodoo magic of Lugosi's character. I was wondering what film was the first to show actually dead and buried zombies, rising from the grave in various forms of decay. Anyone with good knowledge of Zombie movie history lore know? I'd appreciate any help. Thanks!