Twelve years ago, I began researching a family murder that happened in Southern Italy in the 19th century.

It took a decade to find the details of the crime, but the facts I uncovered about the daily life of my ancestors and the racism they faced — even from their own countrymen — were more shocking than the killing.

In today’s climate of refugee bans and xenophobia, the facts have taken on a new urgency and are even more disturbing to me, as they should be to anyone whose family traces its roots to Southern Italy.

Women like my great-great grandmother Vita Gallitelli came to America for more than simply a better job. Subject to the whims of their padroni — the men who owned the feudal land upon which they toiled — Italian women were commonly the victims of institutionalized, systematic rape.

There was a practice known as “prima notte” that allowed the landowner to sleep with the virgin bride of his worker, which extended into the 20th century.

The husbands couldn’t protest, since they would be barred from working the farm and their families left to starve. As it was, they were barely staying alive.

In the 1800s, half the children born in Basilicata — the instep of Italy’s boot — died before age 5. It’s the reason Italian-American families hold big bashes for their 1-year-olds even today.

The itinerant workers were considered subhuman and made 40 cents a day if they were chosen by the overseer, doing backbreaking work on land that was not theirs, walking several hours back and forth to the farm each day.  (All these were the same conditions in France and Latin European countries)

They were expected to offer the padrone a “tribute” to thank him for the work — crops, or if they had it, meat they butchered themselves. This was the basis for the shape-up on the American docks on which many of my relatives toiled when they came to this country and the kickbacks they were expected to give to the union bosses and even the mayor.

In Italy, our ancestors were given meat twice a year — on Christmas and Easter by that same stingy landlord — but most days they subsisted on bread stretched with chestnuts or saw dust to feed the whole family.

So our desperate great- and great-great grandparents came in droves from Italy, spurred on by industrial barons in need of cheap labor who welcomed them with open arms to America. They would scrape together the 300 lire — the cost of three houses at the time — to book passage here, to the land of dreams, where menial, often dangerous jobs no one else wanted awaited them.

Some, like my relatives, came here illegally, under false names. Or as stowaways. On one ship alone, 200 stowaways were found.

From 1906 to 1915, the year Vita died, Basilicata lost nearly 40% of its population to emigration.

The Italian landowners — the same ones who raped and starved my relatives and maybe yours — were devastated by American emigration, left with too few hands to work their land.

The Italian government, initially happy to see its poorest and most troublesome people leave the country, realized that the best and strongest were now leaving as well, looking for a better life and higher wages.

Before a United States congressional commission, a politician from Calabria testified that emigration from the South had gone too far, adding that he was sorry Columbus had ever discovered America.

The United States government used the theories of Cesare Lombroso, a 19th-century Northern Italian doctor, to stop more of his suffering, starving countrymen and women from immigrating.

Lombroso, a traitor to his own people, was convinced that there was such a thing as a “natural born criminal.” He measured the heads and body parts of thousands of fellow Italians — particularly Southerners — and came up with a description that matched the description of most of the immigrants coming over at the time: short, dark, hairy, big noses and ears.

He compared them to lower primates and said they were more likely to commit violent crimes when they arrived in the United States than immigrants from Germany, Norway, Austria, Sweden, England and every other European country.

Lombroso — and a growing sea of American nativists — branded the Southern Italians savages and rapists, blaming them for the crime that was on the rise in the United States.

The United States Immigration Commission concluded in the infamous 1911 Dillingham report: “Certain kinds of criminality are inherent in the Italian race. In the popular mind, crimes of personal violence, robbery, blackmail and extortion are peculiar to the people of Italy.”

The Immigration Act of 1924 barred most Italians from coming into the country — causing immigration from Italy to fall 90 percent. Even though the vast majority of those coming to America were good, honest working people and not criminals.

Italian-Americans who today support the president’s efforts to keep Muslims and Mexicans out of the country need to look into their own histories — and deep into their hearts.

After all, they’re just a couple of generations removed from that same racism, hatred and abuse. Had our ancestors tried to come days, weeks or months after the 1924 ban, we may not have even been born.