Technically, the word "supper" refers to a light meal that takes place in the late afternoon or early evening. While the exact use of the word may refer to a type of meal as well as to the time of day that the meal is served, there is no uniform use of the word "supper" throughout the world.
In colonial days farmers were too busy to eat three meals a day, so they only had breakfast and dinner. The wealthy had three meals a day, breakfast, dinner and supper. Back then dinner was a hearty meal eaten in the middle of the day, and supper was the lighter meal eaten before retiring.
In the 1800s, in households of the upper classes that employed a cook or servant, dinner was served at the end of the day. Supper was eaten in the afternoon and was a lighter meal.
In middle-class homes without servants, dinner was eaten in the middle of the day and supper was the last meal. This practice worked well with people who traveled or lived in encampments, like pioneer wagon trains and Gold Rush seekers.
In the United States today, supper can mean something different in various parts of the country. In the South, supper usually refers to all evening meals when served in the home, probably the kitchen, and among family members.
For many years in the U.S. heartland, supper referred to the meal that took place around nightfall. In the 1930s and 1940s supper clubs, a public dining-out experience primarily open only for the evening meal, became very popular across the country.