I found and converted this Minecraft Classic world from 2009 to

Java Edition Classic 0.0.15a (Multiplayer Test 1) – Minecraft Wiki

Minecraft: The Unlikely Tale of Markus by Goldberg, Daniel

Java Edition Survival Test – Minecraft Wiki

I loaded up my first ever Minecraft world, which I made 11 years ago in the browser version of alpha 0.30 : r/Minecraft

I found archives of old Minecraft Wiki pages. It's amazing how much the game has changed. : r/Minecraft

Minecraft (partially found previous versions of sandbox game; 2009-present) - The Lost Media Wiki

Evolution of Minecraft 2009-2023

Minecraft Tutorial - How To Convert Classic Worlds To Full Minecraft

Java Edition Early Classic – Minecraft Wiki

Minecraft Facts for Kids

Minecraft at 10: a decade of building things and changing lives, Minecraft