The "original" Dungeons & Dragons created by master magicians Gary Gygax and Dave Arneson. It was published in 1974 and is a bit of a far cry from the D&D that was yet to come. But it's amazing to see this early take on the rules.
There were just three classes included: Fighter, Magic User and Cleric. Four races: Human, Elf, Hobbit and Dwarf.
The game was based on the miniatures wargame Chainmail and it borrows heavily from those rules.
There was a supplement released for the game called Greyhawk which further added rules to the base set of three core books (all three core books are included in the white box set). Later, Blackmoor came out as another campaign setting. Several other sourcebooks were eventually released for this early flavor of Dungeon's & Dragons.