Five years before that a former East India Company sailor had planted a few in Savannah, Georgia, and later even figured out how to make soy sauce. In the 1800s there more US soy-growing experiments, and labourers recruited from China and Japan began to bring not only the beans but also a taste for things made out of them. By the time Meyer travelled to China there were dozens of tofu shops catering to Japanese immigrants up and down the US west coast.

Meyer’s beans were part of a concerted effort that by the early 1940s had enabled the US to surpass China as the world’s top soybean producer. His employer, the US Department of Agriculture, was the most important agent of soy’s rise, but there were many others, from agricultural-science professors at Midwestern universities to Seventh-day Adventists in search of protein-rich vegetarian foods to business titan Henry Ford, who envisioned a world in which more or less everything would be made of soy, including cars and clothing.

The US$39,000 “soybean suit” that Ford proudly donned in 1941 was only one-quarter soy fibre, though (the rest was wool). Soy fabrics proved impractical, and most of the other non-food soy uses envisioned by Ford and others in the 1930s and 1940s never panned out.

Despite the spread of Chinese and Japanese cuisine and occasional commercial successes such as Tofutti (cream cheese and ice-cream substitutes), soy milk and the Gardein Holiday Roast, soy has never entirely captured the hearts of American consumers, either. For the past two decades, demand has been dampened somewhat by concerns about soy allergies and side effects of the oestrogen-like isoflavones naturally present in soy.

This has not stopped US soybean acreage and production from continuing to rise, though. It is the second-most valuable crop in the US, not far behind corn and way ahead of everything else, as well as the country’s most important agricultural export.

Those exports have fallen 29 per cent since 2017 because of US President Donald Trump’s trade war with China, but the pain this has caused in the Midwest and the billions of dollars that the Trump administration has paid farmers to assuage it are yet another indication of how important soybeans have become.

Where do all these soybeans go? Mainly into livestock feed at home and abroad. In the US, soybean meal is used most intensively in chicken feed, which is significant because per-capita chicken consumption has more than quadrupled since the 1950s, while beef and pork consumption are down.

The second most important product derived from soybeans is oil. Some of that ends up in inedible products such as wood stains and tyres, but most goes into food. The US produces four times more edible oil from soybeans than from the No. 2 source of vegetable oil, corn.

Few people set out to consume soybean oil, but it’s the No 1 ingredient in Hellman’s Real Mayonnaise and Best Foods mayonnaise, Crisco shortening and Wish-Bone Italian dressing. It’s No 2, after flour, in Ritz crackers. McDonald’s fries are cooked in a mix of soybean oil, corn oil and canola.

This ubiquity of soybeans in the US demands explanation. Historian Matthew Roth’s Magic Bean: The Rise of Soy in America came out in 2018. Almost all the soybean history recited so far in this article is derived from it.

Roth wonders in the introduction to Magic Bean whether the soybean’s American triumph was destined from the start or the result of a succession of lucky breaks. The argument for destiny is that it’s a plant rich in protein that makes an excellent complement to what was already the nation’s signature crop: maize, also known as corn.

With help from bacteria that like to hang out among their roots, soybean plants put back into the soil the key nutrient, nitrogen, that corn takes out. That is why soybeans and corn are usually grown in rotation, together dominating the US agricultural landscape from the middle of Nebraska to western Pennsylvania, from northeastern North Dakota to northeastern Louisiana.

Still, other bean crops fix nitrogen in the soil, too, and – edamame aside – it takes a lot of work to transform soybeans into something palatable and useful. Major investment in soybean-processing equipment and technology had to coincide with major diversion of cropland into soybeans, which is what happened in the 1930s and 1940s.

This was partly the doing of risk-taking private actors such as Henry Ford, Illinois-based soybean processor A.E. Staley and the Glidden Co’s Adrian Joyce, who steered the manufacturer of paints and foodstuffs into soy in a big way in the early 1930s. But it probably could not have succeeded without the US Congress, which repeatedly aided soy without really meaning to.

The yellowish tint of unbleached soybean oil, for example, offered a way around a federal tax on artificially coloured yellow margarine that had been enacted in 1902 at the behest of the dairy industry.

This tax was extended to all yellow margarine in 1932, but a tariff on foreign vegetable oils imposed two years later offered another boost to soybeans. The landmark Agricultural Adjustment Act of 1933, meanwhile, paid farmers to let fields lie fallow in an effort to stabilise agricultural prices.

Crops planted to improve the soil were exempted from the law’s restrictions, which led to lots of acres being planted with soybeans. Most of these were initially just ploughed back under, but the USDA started granting exemptions to struggling farmers that allowed them to use the beans as feed or even sell them.

After World War II, which brought new soybean uses such as the biscuits made of soy, wheat and oat flour that were a key part of military K rations, soybean farmers had become a big enough constituency that Congress began to help them intentionally. The margarine tax was repealed in 1950, and the Agricultural Trade Development and Assistance Act of 1954 began a policy of subsidising food exports that proved hugely beneficial for soy.

Many government actions since then have been aimed at helping US soybean farmers.

Still, the news from Washington has not always been good. In June 1973 the Richard Nixon administration, misreading signals from soybean futures markets that officials thought portended a major shortage, imposed an embargo on soybean exports.

It lasted only a week, but is widely credited with jump-starting the rival Brazilian soybean industry because buyers in Japan no longer felt they could rely on US supplies. The subsequent embargo of the Soviet Union imposed by President Jimmy Carter in 1980 in retaliation for the invasion of Afghanistan may have cemented Brazil’s rise as a major soy power.

China’s economic growth and ravenous demand for soy to feed its pigs subsequently provided a huge new market, enabling US soybean exports to keep growing even as competition from Brazil and elsewhere intensified. About half the soybeans grown in the US in recent decades have ended up overseas, exported mostly as whole beans but also in the form of meal or oil.

Over the past two years, though, China has sharply reduced soybean imports from the US in retaliation for tariffs on Chinese goods imposed by Trump. As recompense, the Trump administration has handed over US$8.6 billion (and counting) in subsidies to soybean farmers, according to an Environmental Working Group analysis of USDA data, with soybean payments now accounting for about one-third of all farm subsidies, up from 11.6 per cent over the past quarter century.

I emailed Magic Bean author Roth, who is now assistant director of the Andrea Mitchell Centre for the Study of Democracy at the University of Pennsylvania, to get his take on these developments, which were too late for inclusion in his book.

After reviewing the negative impact of the embargoes of 1973 and 1980, he concluded: “Whatever the shakeout from the trade war more generally, it looks like the effect on soy farmers may be long-lasting. (Though when it comes to predicting the future, don’t ask an historian.)”

Tensions between China and the US aren’t going away, and like their Japanese counterparts nearly half a century ago, Chinese entrepreneurs and officials are now looking for ways to reduce their dependence on US soybeans. The country can’t feasibly grow enough domestically to meet demand, reports business publication Caixin, so among other things it has been exploring new soybean frontiers just across the border in Russia.

Could Trump end up indirectly launching a Russian soybean industry? Well, stranger things have happened.