Canton First Monday Trade Days has Evolved over the last 155+ years several times. Here is a bit about some of those evolutions and why they happened.
Canton First Monday Trade Days has evolved many times since its inception around 1850. Yet through it all it has run continuously and grown to such a legendary event. As many know, it was called 'horse monday' or 'Hoss Monday" in the vernacular of the times. That was because people in the area rounded up the wild horses and brought them to town to trade or sell. Once the wild horse population was gone it slowly shifted to pigs. There was a time when it was said the best hogs in the world could be found at First Monday trade days. There is still a fairly large wild hog population in and around that portion of east Texas.
Nowadays people refer to dog alley when talking about the animal section of the first monday trade days. You can find almost any kind of domestic animal as well as most legal exotics there at one time or another. Yet dogs are still the number one animal today.
The pavilions have changed much of the grounds into a marketplace, But there are still the open air reserved and unreserved sections Roy referred to in his post below. Here the true flea market and swap meet atmosphere still prevails. Here you can still search through piles of odds and ends to find that one treasure that makes your whole trip worth while.