What do slaves the slaves hired yearly do on New Year’s Eve?

On New Year's Eve the hired slaves pack their things and wait to see if they will be rehired for another year.

From the text:

Then comes New Year's eve; and they gather together their little alls, or more properly speaking, their little nothings, and wait anxiously for the dawning of day. At the appointed hour the grounds are thronged with men, women, and children, waiting, like criminals, to hear their doom pronounced.

Note, this is a Chapter Three question.