ON A RECENT trip to California, I went out for an evening walk in residential San Francisco, in windbreaker weather, with wisps of fog rolling in from the Pacific a mile to the west. There are fern bars on Geary Boulevard, with WASPy-looking customers, but the people walking around seemed mostly of Asian origin. From middle-class rowhouses on the numbered avenues, their windows open San Francisco-style to let in fresh air, I could hear unfamiliar popular music, of some Oriental kind -- was it Filipino or Malaysian or Korean?

I thought of a visit I made a few months before to Gunston Hall, a pre-Revolutionnary mansion in Virginia, and of reading an historian's vivid descriptions of indentured servants being unloaded a few miles from where I live in Washington. I thought of my own ancestors, most of whom came off boats from Italy and Ireland between the 1840s and 1890s and went to work in Boston and Buffalo and Detroit. And for a moment I had an eerie feeling that I was part of a single process of immigration and assimilation, in touch with the experiences of millions of new Americans that extended in time over more than 200 years and geographically across a vast continent.

A new America is being made by immigration. And made rapidly. Over the last dozen years, the United States has experienced the biggest flow of immigrants in the memory of almost any living American. From 1925, the year restrictive immigration acts took full effect, until 1965, when the law was loosened, only about 300,000 immigrants came here each year, less than 100,000 during the Depression and World War II. After 1965, immigration rose slowly, topping 400,000 only once before 1977. Since then it has boomed.

The official immigration total rose from 2.5 million in the 1950s (when there was little illegal movement) to 3.2 million in the 1960s, 4.3 million in the 1970s, and almost that much from 1980 to 1986. Yet these official numbers understate the total, which between 1977 and 1986 probably amounted not to the official 5 million but to 10 million. That makes a dent, even in a country of 238 million people.

Almost no one anticipated this 20 years ago. Few Americans then had any memory of large-scale immigration. In an America that was rediscovering poverty, it simply didn't cross people's minds that immigrants would believe they could make a living here, and would try.

Can the United States absorb this mass of immigrants? Can it assimilate people from such different cultures as Latin America and East Asia?

The instinctive response of many Americans is: No. These new immigrants are more alien than earlier waves and we are less adaptive. We have finally managed, by passing the Immigration Reform Act of 1986, to control our borders once again by punishing employers who hire illegal aliens; total immigration is still limited to 270,000 a year, plus refugees, close relatives and supposedly seasonal farm workers which bring the total up to over 500,000. No one is sure yet how the new law is working. Border crossing statistics -- a rough measure at best -- showed migration down so far this year, but contractors have been resourceful in recruiting farm workers and the flow is likely to continue. Can we assimilate it?

My answer is an unequivocal and enthusiastic yes. We have done it before and we are doing it again. Immigration is as American as apple pie, and large-scale immigration has been a characteristic American phenomenon since before the Constitution and Declaration of Independence.

For proof, go some 20 miles down the Potomac past Mount Vernon to Gunston Hall, the house built by George Mason in 1755. Mason was one of the biggest landholders and slaveholders of colonial Virginia, a friend and mentor of George Washington and Thomas Jefferson. This perfectly proportioned Georgian house seems the essence of native-stock America. But it was built by an immigrant, an indentured servant named William Buckland, a 22-year-old apprentice in London when he agreed to work for the Mason family as an architect for four years, in return for his passage, room and board and 20 pounds a year. Those were generous terms and Buckland was highly skilled; after his four years, he moved to Annapolis and designed many of the Georgian houses still standing there.

The Chesapeake Bay colonies, as Bernard Bailyn describes in his marvellously readable "Voyagers to the West," were swarming with indentured servants in the years leading up to the Revolution. Bailyn portrays the young unmarried men who had (or claimed) skills as carpenters or joiners, as they sailed to the Chesapeake or to Philadelphia, the most thickly-populated and economically advanced parts of the 13 colonies. He tells how these indentured servants were sold on shipboard or off-loaded at Dumfries or Georgetown or Baltimore to middlemen who would peddle their services to planters and townsmen. These migrants were not as easily assimilable as their English origin would suggest: unattached, often untrustworthy, sometimes speaking difficult-to-understand local dialects, they must have seemed exotic and even scary to many locals. But they were ancestors of many people in this area today.

The other great flow of migrants described by Bailyn were families of Scots Highlanders and Yorkshiremen, people with some assets in search of their own land. Through land speculators they found it, landing in New York and Philadelphia and heading to the lands of the Mohawk Valley or down the Shenandoah Valley to the Piedmont of North Carolina. These once distinctive ethnic groups seem to have blended into a single WASP group today -- except perhaps when you look at election figures: North Carolina has been divided since Revolutionary times right up through the 1986 election between the coastal counties (English, Anglican, Confederate, Democratic, segregationist) and the Piedmont (Scots, Presbyterian, Unionist, Republican, moderate on race).

This pattern of skilled immigrants coming to growing areas is apparent in the more familiar immigration of 1840-1924. During the first 40 years immigrants went mainly to the North, the Irish to the cities, others to the countryside. After the Civil War, the big flow was of Germans and Scandinavians into the empty, chilly lands northwest from Chicago. As other parts of Europe advanced beyond serfdom and subsistence farming they contributed immigrants too: southern Italy after 1880, Poland and Russia after 1890. In 1907 immigration reached its peak, with 1.7 million immigrants arriving, most of them at Ellis Island, in a country of 87 million people. This 1880-1924 immigration was largely urban and almost entirely northern. In 1930 nearly three-quarters of the people in New York were of immigrant stock, while the South, preoccupied with maintaining segregation and its low-wage economy, had a population of less than 2 percent immigrants.

"Give us your poor," Emma Lazarus wrote, but we didn't get the poorest, any more than we get Ugandans or Chadians today. Historian John Bodnar reported in "The Transplanted" that immigrants "tended to be concentrated in the middle and lower-middle ranks of society." Immigrants were not the product of subsistence societies, but "the children of capitalism"; they were not rebels against the traditions they knew, but were disposed "toward doing whatever was necessary to sustain a family-based household."

Immigrants encountered some prejudice, even violence, but they also found employers who were willing to pay for their labor and political bosses who were willing to provide services for their votes. Earlier settlers spun theories of ethnic superiority, but they were not acted on until the enhanced power of government in World War I suggested that immigration could be broadly restricted. But even as it was, immigrants were moving upward in American society, away from the crowded slums of Hester and Mott Streets and out the subways to the apartments of Brooklyn and the Bronx, on their way to the suburbs of Westchester and Long Island.

This seems to be happening again. Many of today's immigrants were upwardly mobile even before they got here. This is obvious in the case of many Asian refugees, or of Cuban-Americans, but it's also true of Mexican-Americans. In "Latin Journey," Alejandro Portes and Robert L. Bach traced Mexican immigrants back to their roots and found that "Rather than being illiterate peasants from the countryside, these men originated from the most dynamic sectors of Mexican life." They may look bedraggled and unsophisticated to us, but they are skilled people ready to move upward in the world's most advanced economy.

Again, they go to the most rapidly growing parts of the United States, the largest number to Los Angeles, which today is what New York was in 1907: the number one immigrant destination in the world. These new immigrants are blending in rapidly. There are a few horror stories: Vietnamese fishermen beaten up in a Texas Gulf town, the (liberal Democratic) judge who gave virtually no jail time to laid-off auto workers who killed a Chinese-American in Detroit. But the dispersal of Asians and Latins through metropolitan areas show that they're encountering little discrimination.

Today, the pattern seems to be that the great majority of immigrants know some English, at least well enough to use it in the transactions of everyday life and to watch TV. Despite the efforts of the bilingual teacher lobby to maintain a large enough non-English-speaking population to keep bilingual teachers employed, the children themselves overwhelmingly learn English. They realize that there is only one community in the United States where you can rise all the way up without learning English -- Miami, with its status as the economic capital of Latin America.

Instead of old-time political machines, the American cities where today's immigrants are making their way upward have media-based politics in which voters tend to have a fairly high degree of knowledge of issues and events (otherwise the shorthand of political TV spots would mean nothing to them), but no personal involvement in them. While blacks remain monolithically Democratic and committed to the going-nowhere candidacy of Jesse Jackson, the new Latin and Asian voters are picking and choosing among the candidates and parties, maximizing their clout and making themselves key target groups for politicians of the future.

Democrats used to assume that, like blacks', Hispanics' major concern would be increasing the power of the federal government to combat discrimination and help the poor. But Latin voters have encountered less discrimination and are less likely to be hopelessly poor. As many as 40 percent of Hispanics seem to have voted for Ronald Reagan in 1984; about half of Hispanics voted for the white opponents of Chicago Mayor Harold Washington; in Texas leading Hispanic politicians such as San Antonio mayor, Henry Cisneros and Rep. Kika de la Garza (D-Tex) tend to be somewhat hawkish on foreign policy. Many Latin immigrants don't see Castro or the Sandinistas as benign income redistributors; for them, communist dictatorship and leftist guerrillas are as menacing realities as right-wing dictators and death squads are for others. Moreover, in choosing to come here, they have taken the chip off their shoulders about the Yanquis up North that many Latins back home still wear. Latins don't come here so much to change American society as to enjoy it.

The same seems true of Asians. The tradition of talented Asian-American politicians is Democratic, but on foreign policy many of the Asians favor the Republicans. The Vietnamese and Cambodians, after all, are not unhappy that the United States went into Indochina but that we left.

If the product of the 1770s immigrants is visible in Gunston Hall and the monument of the 1840-1924 immigrants is Ellis Island, you can best see the newest immigrants in that most American of places, Disneyland, in Orange County, California, where about 40 percent of the visitors on my recent trip seemed to be of Latin or Asian stock. These groups, like earlier groups are blending into -- and changing -- American society. Each group has made its imprint, but none has proved unassimilable, and every one has been made to feel, sooner or later, welcome. For all the changes there is a recognizable continuity between the 13 colonies with 3 million people which William Buckland sailed to in the 1750s, and the superpower of 240 million people to which the Asians whose music I heard had come by jet airplane in the 1980s.

Michael Barone is a member of the Washington Post editorial page staff.