Call us a nation of fatties, lard-lovers and super-sized seat-hoggers. But it’s hard to stay lean when the greatest food revolution since the invention of the sandwich is parked enticingly on every street corner.

So excuse me while I hoof it over to the Korilla BBQ food truck to grab my lunchtime Porkinator: a taco filled with pulled pork, bacon, kimchi slaw, shredded cheese and barbecue sauce. Last week we had the Taim Mobile in the neighbourhood offering a kind of Middle-Med falafel fusion. The week before it had been Palenque, a Colombian-themed food truck that had sent out its siren call of beef-stuffed arepas. For us New Yorkers it’s the American dream on a paper plate.

Millions of people eat from food carts and trucks every day. Behind the beef short rib, marmalade-glazed onion and camembert grilled flatbread that I had last Thursday lies one of the key reasons why this country is still a better economic bet than Europe. In a word (well, three words actually): market-driven innovation.

In the same way that Silicon Valley offered Twitter as an improvement on Chinese whispers, the modern food truck is the reincarnation of the old chuck wagon. In 1866, a year after the end of the civil war, Charles Goodnight and Oliver Loving (I’m not making up these names) created the Goodnight-Loving Trail, a main cattle route between Texas and Colorado.

Realising that cowboys ride a lot faster on full stomachs, they retooled an army surplus wagon into a travelling kitchen.

From then on, just like in the movies, every cattle drive had its grizzled gap-toothed chef cooking salted meat and refried beans out of a covered wagon.

At about the same time Charles Feltman, a German immigrant living in Coney Island, New York, added a burner to his wagon and began selling warm frankfurters in a split roll. By 1900 the humble hot dog had joined the hamburger and apple pie as the ultimate patriotic fare.

The urban version of the chuck wagon serviced both day and night workers, a necessity in a culture that made restaurants close at 8pm. Things were going swimmingly until city councils seized on the popularity of the mobile food wagon as an easy way to raise tax revenue.

Crippled by fees and charges, the business soon melted away; but not the vendors, who began converting old train carriages and obsolete horse-drawn streetcars into what we now know as the American diner.

By the 1960s the once proud chuck wagon was itself obsolete. It had become the “roach coach”, referring to the grease-splattered food trucks that frequent carnivals and building sites.

That was the history of mobile cuisine until the recession hit in 2007. The collapse of the housing bubble brought construction projects to a standstill. The food truck threatened to go the way of the streetcar. Yet out of this dire economic situation emerged an example of what helps to make America strong.

In the first instance it is the creative engine fuelled by immigration. In early 2008 a Filipino hotel manager living in Los Angeles named Mark Manguera teamed up with his best friend Roy Choi, a Korean chef, to try out a novel idea: high-concept food in a low-cost form.

The two friends bought a food truck, retooled it to serve a fusion of Mexican-Korean cuisine and came up with Kogi Korean BBQ-To-Go as a name. They made their first sales to hungry Los Angeles nightclubbers on Sunset Boulevard. People couldn’t get enough of their Asian-themed tacos and loved the edginess and bold rule-breaking of this new street food.

Soon Kogi was joined by other entrepreneurial chefs who were keen to take advantage of the flexibility of the food truck to explore the outer reaches of fusion cuisine. It was far less risky to offer kosher Chinese-Cuban out of a van than it was to open a restaurant. But the early food trucks in Los Angeles all suffered from the same drawback: being mobile meant looking for new clients every day.

How Manguera, Choi and others solved the problem highlights another powerful engine in the economy: the speed with which Americans embrace new technology. In a stroke of genius the food truckers began using Twitter, sending out schedule alerts and menu highlights.

Instead of driving around looking for customers, Manguera and Choi were luring them to the truck. They quickly became a media phenomenon and a role model for all food trucks. The popularity of the food truck scene resulted in Roy Choi being named one of the best new chefs of 2010 by Food & Wine magazine.

Earlier this year he played himself in Chef, a film about a disgruntled chef who finds redemption in a food truck.

The US cities that have the highest number of food trucks are, not surprisingly, the ones that are also the most pro-business, the most diverse and with a higher proportion of under-40s. Orlando and Miami lead the pack with Austin and San Francisco not far behind.

Heavily unionised cities, on the other hand, such as Chicago, Boston and New York, where City Hall is synonymous with entrenched interests, are among the laggards. When the food trucks first became popular, Chicago barred them from cooking fresh food, Boston forbade them from selling within 1,000ft of a restaurant and New York made parking in Manhattan almost impossible.

Only recently has public clamour forced these cities to roll back some of their restrictions.

Manhattan is still playing catch-up, but across the river in hipster Williamsburg there’s Smorgasburg Saturday, a weekly open-air food truck festival that has become the glutton’s version of Woodstock. Even my village upstate has got in on the act, inviting food trucks to liven up the square on Thursday nights.

This is the third reason why the United States remains vibrant: the promise that Americans who devise better, cheaper and faster services or products will be rewarded rather than inhibited. The food truck is a lesson in capitalism on a stick, dipped in red sauce.