Long ago, lots of wild chickens lived in India and East Asia (China, Thailand, and Vietnam), and that is where people first domesticated (tamed) chickens, maybe around
7000 BC. Recent genetic evidence shows that people tamed chickens in two different places: in China and in India. Probably the people in each place didn't know that the other ones were also taming chickens.
By about 5000 BC, people in China
were certainly keeping chickens, and by 3000 BC people in India also had domesticated chickens.
People ate the chickens and they also ate their eggs.
Chickens were easy to keep, and small enough to eat in
one meal, so you didn't have to worry about the meat going bad. And you
could eat their eggs as well. Both the meat and the eggs are good sources
Another reason for keeping chickens was the popular sport of cock-fighting, which seems to go back thousands of years. You take two roosters and put them in a cage or pit together and they will fight over the territory. People place bets on which rooster will win. Often the loser dies in the fight.
To find out more about chickens, check out these books from Amazon or from your library:
Chicks & Chickens, by Gail Gibbons (2003). Explains where chickens come from, and what they eat, and so on. For younger kids.
A Chicken in Every Pot: Global Recipes for the World's Most Popular Bird, by Kate Heyhoe (2003). Includes a brief history, and lots of recipes for chicken.
Much Depends on Dinner: The Extraordinary History and Mythology, Allure and Obsessions, Perils and Taboos, of an Ordinary Meal, by Margaret Visser (1999). Background on what you eat, including a chapter on chicken.
Food in Antiquity: A Survey of the Diet of Early Peoples, by Don and Patricia Brothwell (1998). Pretty specialized, but the book tells you where foods came from, and how they got to other places, and what people ate in antiquity. Not just Europe, either!