Density

The Western USA is exactly the same area as Europe.

But the Western USA has about 17 people per square kilometer

while Europe has 101 people per square kilometer.

So if the Western USA had the density of Europe, it would have 500 million people (exactly the population of Europe) more than 6 times it's current 80 million. [1992 figures]

The Eastern USA has a density of 60.7 people per square kilometer.

...thanks to Joe for this idea!

Definitions

Europe Including all countries from Scotland to Spain & Finland to Greece, but excluding Russia and the other former Soviet Republics.

The Western USA (all states west of the Mississippi River excluding Louisiana, Arkansas, Alaska & Hawaii but including Missouri & Minnesota) Arizona, California, Colorado, Idaho, Kansas, Minnesota, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Texas, Oklahoma, Utah, Washington, Wyoming

The Eastern USA Alabama, Arkansas, Connecticut, Deleware, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisana, Maine, Massachusetts, Maryland, Michigan, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virgina, West Virgina, Wisconsin, Washington DC

Not Included Alaska & Hawaii

mrk.'s Size Comparisons

Density

The state of Washington , where i live, is larger than every state in the Eastern USA,
but it is the smallest state in the Western USA!!

Definitions

The Eastern USA (all states east of the Mississippi River. Louisiana, Arkansas, Iowa, & Missouri, which are on the river, are counted as Eastern USA because they are traditionally thought of as part of the East.) Alabama, Arkansas, Connecticut, Deleware, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisana, Maine, Massachusetts, Maryland, Michigan, Missouri, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virgina, West Virgina, Wisconsin, Washington DC

The Western USA (all states west of the Mississippi River excluding Alaska & Hawaii. Louisiana, Arkansas, Iowa, & Missouri, which are on the river, are counted as Eastern USA because they are traditionally thought of as part of the East.) Arizona, California, Colorado, Idaho, Kansas, Minnesota, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Texas, Oklahoma, Utah, Washington, Wyoming

Not Included Alaska & Hawaii

Definitions
Europe	Including all countries from Scotland to Spain & Finland to Greece, but excluding Russia and the other former Soviet Republics.
The Western USA	(all states west of the Mississippi River excluding Louisiana, Arkansas, Alaska & Hawaii but including Missouri & Minnesota) Arizona, California, Colorado, Idaho, Kansas, Minnesota, Missouri, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Texas, Oklahoma, Utah, Washington, Wyoming
The Eastern USA	Alabama, Arkansas, Connecticut, Deleware, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisana, Maine, Massachusetts, Maryland, Michigan, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virgina, West Virgina, Wisconsin, Washington DC
Not Included	Alaska & Hawaii

Definitions
The Eastern USA	(all states east of the Mississippi River. Louisiana, Arkansas, Iowa, & Missouri, which are on the river, are counted as Eastern USA because they are traditionally thought of as part of the East.) Alabama, Arkansas, Connecticut, Deleware, Florida, Georgia, Illinois, Indiana, Iowa, Kentucky, Louisana, Maine, Massachusetts, Maryland, Michigan, Missouri, Mississippi, New Hampshire, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, South Carolina, Tennessee, Vermont, Virgina, West Virgina, Wisconsin, Washington DC
The Western USA	(all states west of the Mississippi River excluding Alaska & Hawaii. Louisiana, Arkansas, Iowa, & Missouri, which are on the river, are counted as Eastern USA because they are traditionally thought of as part of the East.) Arizona, California, Colorado, Idaho, Kansas, Minnesota, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oregon, South Dakota, Texas, Oklahoma, Utah, Washington, Wyoming
Not Included	Alaska & Hawaii