BELOIT, Wis. — So much stuff, so little space.

That's the reality o'er the land of the free and the home of the brave. The accumulation of stuff — junk that might not get a second look at a garage sale or gain any visual notoriety at the local landfill — is creating a mark of economic distinction in America.

We may no longer be the top dogs in the production of steel, cars, televisions and other manufactured goods, and we may be losing our edge in science and technology. But the explosion in the number of self-storage facilities clearly suggests a resurgent America, indeed a nation of stuff.

ACCUMULATION NATION

There are at least 55,000 self-storage facilities scattered around the nation, according to the Self Storage Association, double the number of a decade ago. Veterans in the business, who have reaped the benefits of this booming economy of accumulation, say that figure is almost certainly low. The tally of large, aluminum-sided garages, abandoned warehouses and other boxy buildings converted to self-storage units built to hold items that no longer fit at home could approach 100,000, they say.

The economics of stuff is thriving in Rock County, Wis., where, according to the Self Storage Association, there are at least 15 square feet of storage space available for every man, woman and child in the county. (The national average is 6.9 feet per capita.) Nearly all of it is filled. A small but colorful portion of it belongs to 75-year-old Jim Johnson, a retired roofer and committed, unapologetic pack rat who lives in Beloit.

Six days a week, Johnson visits his 12-by-48-foot storage space, a gloriously cluttered museum of desks (four of them), tools, fishing gear, pails of roofing nails, broken radios, a rusty radiator and Heineken signs. (And those are just the highlights.) He starts his day with a little prayer and then he settles back into an old swivel desk chair, drawing comfort from his surroundings.

"I can't throw this stuff away," Johnson says affectionately. "I might need it sometime."

Johnson has rented this metal refuge on a concrete slab for at least a decade. Married for 53 years, Johnson said his wife, Novell, is delighted to not have to look at all his stuff.

"She's been over here three times in 10 years, and she's never gotten out of the car," Johnson said.

New homes are 40 percent bigger than three decades ago, says the National Association of Home Builders. Still, the accumulation of stuff is outpacing the square footage to hold it all.

"The dirty little secret in this business is if Americans ever stop keeping their junk, we're in big trouble," said Cris Burnam, president of Columbia, Mo.-based StorageMart Partners, which operates 60 storage facilities in 12 states.

"We have folks who pay thousands of dollars in storage fees for stuff that you literally wouldn't get a hundred dollars for in a garage sale, but it's their stuff and it has special meaning to them," Burnam said.

Economists regularly monitor production and consumption, imports and exports and just about any measure that reflects the behavior and overall well-being of consumers. But the economics of old stuff that has accumulated over the years is not tracked on the radar screen. The growth in the self-storage industry mirrors a changing America, influenced by birth rates, divorce, lifestyle, housing prices and — most important — affluence.

JUNK MAUSOLEUMS

"Thirty or 40 years ago, people had more kids and less stuff. Now they have fewer kids and more stuff," said Robert Hartwig, chief economist at the Insurance Information Institute. "Part of this is simply affluence in America. Each and every family member has more possessions now."

Consider Footville, Wis., population 832. The town lost its variety store in the past year. But it has two self-storage facilities.

"People have too much money, and they buy too many things," said Kay Demrow, archivist of the Luther Valley Historical Society, in Footville.