Handwritten by Belgian schoolgirls caught in the middle of an adult clash, the letters from 1915 are frank and brimming with gratitude. Germany had invaded their country, British allies mounted a blockade to starve out the German soldiers and millions of innocent Belgians faced starvation at the outset of World War I.

"I do not yet fully understand the meaning of war, poverty, starvation, these words I hear so often at home." 7-year-old Maria Clerbois wrote. "All I know from what my dear papa has told me is that without the great and generous America, we would be suffering great hardship."

The Great War raged for three years in Belgium and the muddy trenches of France before the United States joined the fight in 1917. But U.S. humanitarian aid had started pouring in years before — including tons of wheat milled in Minnesota. Nearly a quarter of the first 283,120 sacks of flour shipped to Rotterdam in January 1915 came from Minneapolis millers.

"At the outset of this frightful calamity that is striking us, we could only look ahead with terror … [and] the threat of starvation," another student wrote in 1915 from Liege, Belgium. "One day, just as all hope of receiving food supplies was vanishing, America the brave and the beautiful came to promise us relief and to give us bread to survive …"

A traveling exhibit of these translated letters — "When Minnesota Fed the Children of Europe" — is coming to the Mall of America this week with a free, virtual opening Monday at noon. (To register, go to tinyurl.com/Belgianlettersexhibit.)

"This was the largest humanitarian relief effort in human history and much of this food aid was wheat flour coming from Minnesota," said Mark Ritchie, the former Secretary of State who's now president of Global Minnesota. The nonprofit group promotes international education and is bringing the exhibit here for the rest of the month.

The girls' letters were written generally to their American peers, but two unlikely men with Midwestern ties were pivotal players behind the massive relief effort that helped feed 150 million Europeans a century ago, from 1914 to 1923.

Iowa-born Herbert Hoover is mostly remembered for a woeful presidency that included the 1929 stock market crash and the ensuing Great Depression. But 12 years earlier, President Woodrow Wilson tapped the Stanford-trained mining engineer to feed Belgium as the head of the federal Food Administration.

Hoover, in turn, named Minneapolis milling mogul James Ford Bell to head the Food Administration's influential Milling Division in 1917. Eleven years before Bell founded General Mills, he had replaced his late father, running the Washburn-Crosby mill in Minneapolis.

Bell resigned his milling job to accept the government post, spending "nearly every night on trains between New York and Washington," according to his obituary in 1961. Bell and Hoover invoked government regulations, including price controls, that stretched wheat production — enabling more than 6 million metric tons of flour to flow to Europe between 1917 and 1919.

"James Ford Bell worked the millers, Herbert Hoover did the organizing, fundraising and negotiating with the Germans, British, French, U.S., etc.," Ritchie said, "and the Washburn A Mill did the heavy lifting."

Bell left the government and returned to Minneapolis in 1919 after the war — but not before earning the prestigious Belgian Order of the Crown and the French Legion of Honor.

He would go on to consolidate several operations into General Mills in 1928 and is credited as the force behind such household brands as Betty Crocker, Wheaties and Cheerios.

Bell was a Republican who opposed New Deal government expansion in the 1930s. But he spearheaded a voluntary relief drive for those unemployed during the Depression and urged his business colleagues to avoid wage cuts for their workers.

Born in Philadelphia in 1879, Bell moved to Minnesota at age 9 when his father, James Stroud Bell, became president of the Washburn-Crosby mill. The younger Bell graduated with a chemistry degree in 1901 from the University of Minnesota — a school at which he would later serve as a longtime regent and benefactor.

Among other things, he financed construction of the Coffman student union and bequeathed his rare book collection to a library that bears his name.

He was "a massive man, still tall and alert," according to a reporter who interviewed him five months before his death in 1961 from a respiratory ailment. He died at 81, just two weeks after his wife of nearly 60 years, Louise, suffered a fatal heart attack in Hawaii. They had four children.

"As you grow older," Bell said in that '61 interview, "you get a sense of responsibility and obligation toward life. If it rewarded you, it makes you want to return something."

That lesson of gratitude echoed what the Belgian school girls expressed for his efforts during the first World War nearly 50 years earlier.

Curt Brown's tales about Minnesota's history appear each Sunday. Readers can send him ideas and suggestions at mnhistory@startribune.com.