Every major version of
https://512pixels.net/projects/default-mac-wallpapers-in-5k/Mac OS XmacOS has come with a new default wallpaper. As you can see, I have collected them all here.
While great in their day, the early wallpapers are now quite small in the world of 5K displays.
Major props to the world-class designer who does all the art of Relay FM, the mysterious @forgottentowel, for upscaling some of these for modern screens.