The reasons may be found in the chapter in this book on California.

Then I named the states just west of the Middle West, and east of New Italy, New Arabia.

These states are New Mexico, Arizona, Utah, Colorado, Wyoming, Idaho, and Montana.

These are the states which carry the Rocky Mountains north toward the Aurora Borealis, and south toward the tropics.

Here individualism, Andrew Jacksonism, will forever prevail, and American standardization can never prevail.