The Box belonged to the Men Of Letters and is decorated with their crest - the Aquarian Star. Inside The Box contains the key to where they had stored all the knowledge that they had possessed. If The Box were to be hunted down by an 'evil being' (demons, monsters etc) it can be safely stored in the area that they had placed all there scrolls and secrets since the area itself is branded with symbols to ward off every evil ever created.
In 1958 Abaddon, one of the Knights of Hell, was sent by party or parties unknown to kill the members of the group who were gathered in Normal, Illinois. They were gathered for the initiation of Henry Winchester and Josie Sands.
Abaddon killed David Ackers and Ted Bowen, and blinded Larry Ganem. She than went on to burn down their quarters before following Henry through the portal created by his Blood Spell. Henry has with him The Box, entrusted to him by Larry which contains the key to where all the knowledge the Men of Letters has collected is stored. It is later learned that the organization has been disbanded after the Abaddon incident. The only known survivors of that incident were Henry and Larry but both of them were killed by Abaddon in her search for The Box in 2013.