Tbh, I can’t remember. I think it was a package, or at least downloadable from the EOS site somewhere. Contained all the old “version name” wallpapers. Or was it in fact @UncleSpellbinder’s Wallpaper Pack? Or the one in the KDE store? Or any of the many others oit there…Hmm…
I was young, I needed the wallpapers. 
EDIT: Damn, I did it again! It was the thingy in the Welcome app that immediately starts a git clone! Argh…
Now to clear the ~/.cache/eos-download-wallpapers.cmcHv/ again …