The Quick Answer
Stockings are tied to legends of St. Nicholas leaving gifts for children, and became a fixed part of Christmas Eve in the 1800s.
The Story
In many European traditions children left out shoes or boots on St. Nicholas' Eve (December 5) to be filled with small treats. In the English-speaking world this became stockings by the fireplace. The 1823 poem 'A Visit from St. Nicholas' (“'Twas the Night Before Christmas”) described Santa filling stockings, which helped fix the custom in North America.
Legend vs. History
Legend says St. Nicholas secretly dropped gold for three poor sisters, and it landed in stockings drying by the fire. This is folklore — the original story mentions gold, not stockings.
Tell the Kids
“There's an old story about a kind man named Nicholas who left secret gifts for people who needed help. Stockings remind us of his surprise kindness.”
Did You Know?
In the Netherlands, children still put out a shoe for Sinterklaas — sometimes with a carrot for his horse.
Try This Tradition
Add one 'kindness note' to each stocking — something that person did this year that made someone else happy.