According to Southern folklore, eating these foods on New Year's Day will bring luck and prosperity. The peas supposedly represent coins and the greens represent paper money. Some families place a penny in the pot while preparing the meal, and whoever ends up with the penny in his or her bowl will have good fortune all year. People also say that collard greens and black-eyed peas are "humble" foods. So, if you start off the year on a humble note, you'll find prosperity.
The tradition of eating peas at the start of a new year goes back to the Civil War. Soldiers ravaged the countryside in search of food, but left the black-eyed peas behind, mistakenly believing them to be cattle feed. The local folks felt lucky that they themselves still had food.