After a century of tumultuous change and growth, at the start of the 21st century New York remarkably had come to resemble nothing so much as New York at the start of the 20th century. The differences over the intervening decades — technological, cultural, urbanistic — were obvious. But in one crucial aspect, its demographics, the city had returned to its roots. New York was once again a city of immigrants.

Door Was Shut
It had not always been so. Despite the popular vision of New York the great immigrant city — home to the Statue of Liberty, Ellis Island and Manhattan's sprawling patchwork of ethnic neighborhoods — for much of the 20th century (specifically, from the late 1920s to the early 1970s) New York had been an American-born city, especially after the "golden door" described by New York poet Emma Lazarus had been shut tight in 1924 by federal immigration quotas that reduced the flood of newcomers to a trickle. By the 1950s, more than 80 percent of New Yorkers were native-born.

Sheer Numbers
The passage by the U.S. Congress in 1965 of the Hart-Celler Act, which reopened widespread immigration to America, would have a dramatic impact on the human fabric of the city. In the 1970s, over 800,000 newcomers streamed into New York. In the following decade, over a million. By the 1980s, the city's population was being dramatically transformed, not only by the sheer numbers of newcomers but their geographic diversity, which far exceeded that of the great immigration a century before, when the vast majority had arrived from Europe.

Immigrants From Everywhere
The city was now the destination point for people from every corner of the globe — businessmen from South America, Russian Jews fleeing oppression in the Soviet Union, refugees from across Southeast Asia, escaping the turmoil that followed the American departure from Vietnam. Millions of others — from the Caribbean, the Indian subcontinent, and central Africa, from China, Mexico, Greece, Turkey, and literally dozens of other countries — were drawn by the city's new prosperity and by its age-old promise of economic opportunity, now burning brighter than it had in decades.

The World Trade Center
Nowhere was this sense of opportunity more obvious than in the World Trade Center itself, whose floors now resembled a miniature United Nations, filled with Sikh computer programmers, Israeli accountants, and financial experts in "emerging markets" who themselves hailed from Malaysia and Syria and Uruguay. By the start of the new century, the 79 employees at the Windows on the World restaurant would include immigrants from 30 different countries, including Barbados, Ghana, and Bangladesh, while the window washers scaling the buildings' exterior would include Poles, Yugoslavs, Albanians, Turks, and Irish.

The World in a City
By the late 1990s, as the migration continued, the city seemed to present itself as an astonishing example of the social and economic possibilities of a complex, multi-cultural society. Whatever its tensions and conflicts, New York — the world's most diverse gathering of nationalities, religions, races and ethnic groups, home to people speaking 180 languages — had become a remarkably safe, secure and prosperous place, where most people, most of the time, managed to get along on a daily basis without violence. Thanks to immigration, it was also simply bigger than ever before. In the year 2000, the Census Bureau reported that city's population — after shrinking for decades — had shot up by more than 700,000 people in less than a decade, topping the eight million mark for the first time in its history.