The 1933 Chicago World's Fair was christened "A Century of Progress." A lot had changed since the first world's fair in 1893: zeppelins soared, Ford's assembly line had brought automobiles to the masses, and pre-fabricated homes were the wave of the future.

And eugenics was now considered by many to be a legitimate science. As such, it received its own exhibit at the fair. One panel in the eugenics exhibit showed the genealogy of the best family in America: the Roosevelts. Juxtaposed to that was another panel, showing the genealogy of the worst family in America: the Ishmaels.

"Among certain charity workers and eugenicists at the time," says Nathaniel Deutsch, a history professor at UC Santa Cruz and author of Inventing America's "Worst" Family, "any poor white Upland Southerner living in or around Indianapolis could just be called an Ishmaelite or a member of the Tribe of Ishmael as a way of stigmatizing them."

By the 1930s, the term "Tribe of Ishmael" had come to designate thousands of people who were not all part of the biological same family — though eugenicists sought to prove hereditary connections between them. They were "a group of degenerates found in Indiana, Kentucky, Ohio, Illinois, Missouri and Iowa," claimed a leaflet from roughly 1921, which tallied 10,000 so-called Ishmaelites. They were "paupers, beggars and thieves, criminals, prostitutes, wanderers." The leaflet conceded that "some have become good citizens," but "the great majority are still mating like to like and producing unsocial offspring."

But there was an original Ishmael family, bound by blood rather than socioeconomic status. They had been in America since colonial times, and one forefather had even fought honorably in the Revolutionary War. So how did they get such a bad reputation?

The original Ishmaels were part of a large mid-19th century migration of rural, white Upland Southerners — people from places like Kentucky, Tennessee, Virginia, West Virginia and parts of North Carolina — to industrial cities further north. "This was before the wave of black migrants from deeper South, what's called the Great Migration," says Deutsch. "The movement of rural whites from the South to the North is less acknowledged in US history."

Often it was the poorest Upland Southerners who were inclined to move. The Upland South was a society based on land use, and as generations proceeded, there just wasn't enough to go around. The Ishmaels were thus likely the poorest branch of an already poor Kentucky family when they arrived in Indianapolis around 1870.

Indianapolis was growing fast in the mid to late 19th century. Poor white Upland Southerners like the Ishmaels arrived in droves, but so too did middle- and upper-class whites from Northern and Eastern cities, hoping to cash in on the industrial boom. The cultures clashed: like any group of migrants, the Upland Southerners brought with them regional customs, some of which were abrasive to their wealthier counterparts.

According to accounts in Deutsch's book, the Upland Southerners were fond of whiskey, dogs, fiddles and fistfights. They hunted for their dinner, and preferred lively evangelical revivals to established church congregations. Many drifted in and out of the city in search of seasonal work. Some were marginally housed , sleeping in makeshift encampments by the river, or even in hollowed out tree trunks. Perhaps most importantly, many refused to hold down steady jobs in the new factories.

The Ishmaels weren't the only poor white Kentuckians to move to Indianapolis, or to refuse to assimilate to the new socio-economic regime, but they stood out. Deutsch suspects that one contributing factor was their surname, which carried sinister connotations.

"Anyone with a basic Biblical education would have known about the way that Ishmael is described in the Bible," says Deutsch. Having been born to a slave woman, Ishmael was disinherited by his father Abraham and banished to the wilderness, where he learned to fight. "He will be a wild donkey of a man," the Bible says. "His hand will be against everyone, and everyone's hand will be against him."

In the Bible, Ishmael and his offspring, the Ishmaelites, were doomed to poverty, confined to the margins of society, and inclined toward violence. In the 19th century, to be called an Ishmaelite was to be called an itinerant savage.

The family's Biblical namesake was not lost on the minister Oscar McCullough, who "discovered" the Tribe of Ishmael in 1878. McCullough was a newcomer with Northeastern roots, born in Ohio to a family from New York and Connecticut, and educated in Chicago. In Indianapolis, he became immediately involved in organized charity, making visits to residents of slums with names like Poverty Flats and Greasy Row.

On one such house call, he encountered a family of seven living in a single room, ten feet by ten feet. They were all blind. They were the Ishmaels.

McCullough developed a keen interest in the family. He believed they had been given the derogatory name Ishmael because of their wandering ways (Deutsch, however, has determined that the family arrived on the continent with the surname, likely from Wales). He was the first to call them the "Tribe of Ishmael" and the "Ishmaelites," emphasizing their itinerancy and nomadism.

McCullough was inspired by a book published the year prior by sociologist Richard Dugdale called The Jukes: A Study in Crime, Pauperism, Disease and Heredity. In it, Dugdale had sought to examine the existence of a vagabond family — given the pseudonym "Juke," meaning a bird that has no nest — using a combination of environmental and hereditary explanations. With the Ishmaels, McCullough set out to do the same.

"Eugenics itself was really a nascent movement," says Deutsch, "and McCullough was a pioneer, even though he wasn't really a eugenicist per se." McCullough believed that the Ishmaels, despite their bad genes, could improve their conditions, if given adequate charity, opportunity, and education.

"Of all the individuals in the eugenics movement who took interest in the Ishmaels," says Deutsch, "he was the most sympathetic to the family. Certainly he could never imagined what turns the story would take."

Benevolent though he may have been, McCullough believed that pauperism was a moral failing, but one that could be corrected through social engineering. Over the next decade, he built up the Indianapolis organized charity system and fashioned it after his own vision. His programs sought to encourage charitable giving and to discourage begging, striving for a perfect equilibrium. "While the poor we will always have with us," he said, "it is our fault and our disgrace if we have the pauper."

All the while, he kept a close eye on the Ishmaels and wrote about them extensively, with the goal of demonstrating a worst-case-scenario of pauperism run amok. The blindness, he determined, was caused in some cases by syphilis, and in other cases by blue vitriol, a substance that allowed people to feign sight loss and made begging more profitable. In both cases, the disability was a sign of poor virtue: sexual licentiousness on the one hand and being a beggar on the other.

McCullough exaggerated the family's criminal activities, stating that the Ishmaels were responsible for the first murder in Indianapolis (placing them in the city three decades before they actually arrived). "Like any group of poor people," says Deutsch, "you'll see some who are receiving aid of some kind, some who are engaging in various kinds of informal economic activities, and some who were petty criminals." McCullough emphasized the latter, at times seeming to conflate criminality in Indianapolis with being an Ishmael, describing the family as a "pauper ganglion" that was five thousand people strong.

The eugenics movement was barely underway, but McCullough's study of the Ishmaels contained a strain of early eugenic thought. He believed that Anglo-Saxon people were inherently superior, but he also believed that poor breeding could cause hereditary deficiencies, even within the Anglo-Saxon demographic.

The Ishmaels, in his opinion, were the worst of the best. Through poor breeding they had devolved to a more primitive state — "an animal reversion," he wrote. He speculated that their ancestors were damaged on arrival, "from the old convict stock England threw into this country in the seventeenth century."

In 1907, Indiana became the first state to pass a law permitting the sterilization of "confirmed criminals, idiots, imbeciles and rapists." (Wikimedia)

As time went on, McCullough sought a larger audience for his theories. Nationwide, people were rapt. Eventually, the story of the Ishmaels was out of McCullough's hands. In the early 20th century, the Ishmael family became an object of fascination for actual eugenicists, scientists who spoke of germ plasm and cacogenics (corrupt genes) and believed that itinerancy was a "sex-linked, recessive, mono-hybrid trait."

Poor whites were a major preoccupation of early 20th century American eugenicists. They were the exception that proved the rule — that is, the "fact" that even Anglo-Saxons were susceptible to hereditary degradation proved the importance of keeping the gene pool clean.

McCullough's milder proposals included being mindful of how charity was administered. His most extreme proposal was that children be taken from the Ishmaels and raised elsewhere, so they could be reformed, against their inborn tendencies. But unlike McCullough, the eugenicists of the early 20th century didn't believe that improved home environments would benefit the children of the white underclass. They believed these children were predestined by permanently damaged genetic material. Therefore, they proposed sterilization.

In 1907, Indiana became the first state to pass a law permitting the sterilization of "confirmed criminals, idiots, imbeciles and rapists." The Ishmaels were invoked in the drafting of the legislation, under which over 2,300 people were sterilized. The Committee on Mental Defectives, which oversaw the identification of "idiots" and "imbeciles," was founded by Amos Butler, the secretary of McCullough's charities. Indiana had become, in Deutsch's words, "a veritable eugenics laboratory."

Dr. Amos Butler in 1900. (Library of Congress)

The Ishmaels were invoked again in the 1920s, this time on the national stage. Congress was considering the Immigration Restriction Act, which would limit the number of new immigrants by ethnic quota. "The Ishmael family was brought into congressional testimony as an example from the colonial period of what could go wrong if you allowed immigrants to come into the U.S. in an unregulated fashion," says Deutsch. "The argument was, 'Look, if even a great place like Great Britain could produce these people, imagine what a place like Poland or Italy could do.'"

Senator Ellison DuRant Smith also argued in favor of the Immigration Act, declaring during the senate debate, "Thank God we have in America perhaps the largest percentage of any country in the world of the pure, unadulterated Anglo-Saxon stock; certainly the greatest of any nation in the Nordic breed." The legislation was approved by both houses, and signed into law by Calvin Coolidge in 1924.

The World's Fair in Chicago was nearly the last time the Ishmael name was broadcast to the greater American public. World War II rendered eugenics unfashionable — or, as Deutsch suggests, in some cases simply drove it underground. Family studies like the Jukes and the Tribe of Ishmael looked a bit uglier in the afterglow of the Holocaust.

For half a century, the Ishmaels were in the eye of the beholder. But all the while they were real people, weathering the indignities of poverty the best way they knew how.

Nowadays, their descendants live throughout the Midwest, and the stigma of being an Ishmael is erased. "Rather than a cacogenic clan," Deutsch writes, the contemporary Ishmaels are mostly "comfortable middle-class Americans."

They, and thousands of other descendants of poor Upland Southerners demonized at the turn of the century, are living proof that heredity is not predestination—no matter how badly eugenicists wanted to believe in the myth of the worst family in America.