You're right, I should have been more specific. I meant most cities or populated areas, and I know of few east of the Mississippi that allow chains in the winter due to the effect that they have on road infrastructure in cities that plow. I'm a city slicker though.
In wilderness or sparsely populated areas in the west, or completely snowbound areas anywhere in the country, I'm sure you're fine as long as you don't go into certain cities which prohibit them. Call your city or township hall, or state transportation department if you're unsure on the chains.
It's probably all moot unless you're really in a snowbound area, though. I'm sure the Jeep can handle whatever you throw at it without chains. I haven't tried the Commander in snow yet, but when I lived in Michigan our Cherokee would power through two or three feet of snow without a problem on radial tires.