The state of Texas requires that you have 2 plates. One in front and one in the rear.
Two
Texas law requires all vehicles registered in the state to have both a front and rear license plate. Furthermore, no portion of a license plate can be obstructed by anything including a license plate frame or it is violation of Texas law.
Two , one for the front and another for the rear of the vehicle .
They only require one.
There are 120 different license plates available!
IIRC, the state of Ohio requires two number plates to be displayed.
1 or 2
One on the front of the tractor, and one on the rear of the trailer.
The 2017 Illinois license plates were manufactured at the Illinois Department of Corrections' prison facility in Vandalia. This location has been responsible for producing license plates for the state for many years. The facility employs inmates to work on the production of these plates, contributing to rehabilitation efforts through vocational training.
Two
Two plates were required for automobiles and for trucks. I have a 49 F 1 Pickup that has the original license plates on it.