In the order of popularity they are:
Though Peterbilt only accounts for a small percentage of the commercial trucks on the road they have seen a spike in their popularity. They seem to hold their overall value, but also can be a bit more costly when you visit Peterbilt dealers.
Peterbilt Motors Company is currently headquartered in Denton, Texas. It also has a manufacturing facility there, and in Sainte-Thérèse, (Quebec, Canada).
They got their start in Oakland California back in 1939 and have seen many changes since that time.
Originally the Peterbilt was designed for the logging industry. They needed a vehicle capable of handling the rough terrain of the mountains. After all they needed something better than mules and steam powered vehicles.
The Great depression had created an environment where they were able to purchase the facilities needed to manufacture their own vehicles.