To understand how truly un-American U.S. President Donald Trump's immigration ban is, how out of step with the country's best values, consider the story of his hometown.
For the first two centuries after its founding, writes George Washington University professor Tyler Anbinder in his 2016 book City of Dreams: The 400-Year Epic History of Immigrant New York, newcomers didn't go through any checks at all. They needed no passport, no visa. Even after doctors began boarding ships to examine them for disease around the time of the American Revolution, the immigrants "simply walked off their ships and onto the streets of New York to begin their new lives in America."
When New York finally set up its first immigrant depot, Castle Garden at the southern tip of Manhattan, it was not to protect Americans from potentially dangerous newcomers but to protect the newcomers from potentially dangerous Americans. Touts and thugs had been preying on the confused arrivals as they disembarked at the docks. Castle Garden funnelled them to one place, where police could keep watch.
Eventually, authorities replaced Castle Garden with the famous clearing house on Ellis Island, now a popular museum. It saw its first arrival in 1892, when 17-year-old Annie Moore arrived from Queenstown, Ireland. By then, the United States had introduced the first real curbs on open immigration, barring paupers, polygamists, Chinese labourers, the mentally ill and those with "loathsome" illnesses.
Still, most of the millions who arrived at Ellis Island passed through successfully in just a few hours. The museum says only about 2 per cent were denied entry to the United States, often because they were carrying a contagious disease. First- and second-class ship passengers didn't have to go to Ellis Island at all.
So the idea that the country should treat immigrants as inherently suspicious, much less subject them to Trump-style "extreme vetting," is pretty new in historical terms. It is a distinctly modern notion that every nation is a watertight compartment that must be sealed against threatening new arrivals to prevent it from foundering.
It was only after the First World War that U.S. authorities began to suppress mass immigration in earnest. As Dr. Anbinder points out in his timely book, the war churned up suspicion of foreigners. In the postwar Red Scare, fuelled by the Russian Revolution, police rounded up foreign-born communists and other suspected radicals. Legislation in 1921 and 1924 cut back sharply on the number of immigrants permitted to enter from eastern and southern Europe. Building on earlier limits on Chinese, Japanese and other Asians, the new laws signalled that the United States was turning away "from its historic role as an asylum for the world's huddled masses."
The latest immigrants, it was said, were simply too foreign to make good Americans. Many Americans came to see them as a shadowy fifth column – clannish, disloyal and a danger to American security. Weren't many of those anarchists Jews or Italians? Must not most Jews and Italians therefore be anarchists or anarchist sympathizers?
"Immigration of this character is invasion, and invasion means conquest," the Chicago Tribune said. "For America, shut the gates."
The echoes in today's headlines are unmistakable. When Mr. Trump decreed Washington would slap a temporary ban on refugees and block the entry of people from seven mainly Muslim countries, his executive order said that "The United States must ensure that those admitted to this country do not bear hostile attitudes toward it and its founding principles."
All of this has happened before. In colonial New York, it was the Catholics who were supposed to be a threat to American security, because they would ally with Britain's Catholic foes. Later it was the Irish, still later the Germans. In its moving new Super Bowl ad, Budweiser reminds Americans of the danger and hostility newcomers like the brewery's co-founder Adolphus Busch had to overcome.
"Yet prior to the 2016 election campaign," Dr. Anbinder says, "no prominent member of any American political party … ever proposed banning an entire ethnic or religious group from immigrating to the United States because of the sins of a few of the group's members."
In his own twisted way, Mr. Trump is making history.