Where do D&D Orcs come from?

I’ve always assumed that with all modern fantasy, D&D included, their racial archetypes for their inhabitants always had their roots from Tolkien’s Lord of the Rings. And in part, I do believe there is enough healthy evidence to indicate that many of D&D’s Orc characteristics are indeed inspired from Tolkien’s Orc, whether it’s their physical prowess, inherent brutality (although this is likely to change very soon), militaristic organisation, etc.

But where do they really come from? Tolkien’s Orc stems from enslaved and corrupted elves who had their humanity literally tortured out of them. Where do D&D orcs come from and what makes them what they are?