The Lottery--Shirley Jackson
The black box in "The Lottery" represents tradition. According to the story, Mr. Summers often suggested making a new box, as the black box was shabby, but no one wanted to do anything. The reason for this is given; no one wanted to tamper with tradition. Here is what the text says:
Mr. Summers spoke frequently to the villagers about making a new box, but no one liked to upset even as much tradition as was represented by the black box.
Furthermore, we can see how much the people venerated the box, because the current black box was made with original pieces of the first one. Here is what the text says:
There was a story that the present box had been made with some pieces of the box that had preceded it, the one that had been constructed when the first people settled down to make a village here.
The accent on tradition is important, because the village continues this ritualistic murder based on tradition. No one really knows why they continue the lottery. All they know is that they have been doing it for a long time.
In addition to this point, the box also symbolizes death. When people draw from the black box, they are drawing more than a piece of paper. They are drawing to see who will die. In this sense, the black box symbolizes death.