AT DAWN the other morning I stood on one of my secret Washington overlooks, the alley behind the 1900 block of 39th Street NW, and surveyed the silent city below. It could have been the rooftops of Paris spread out there before me, the new Paris Maj. Pierre L'Enfant dreamed of creating as he tramped through the forest here two centuries ago. The 36-year-old engineer studied Jenkins Hill and the crescent of other high points that demarcated the fall line. Then, in March 1791, he reported to President Washington in his characteristically fractured English of the "most desirable position" the heights offered "for to Erect the the Publique Edifices thereon -- from these height every grand building would rear with a majestied aspect over the Country all around and might be advantageously seen from twenty miles off . . . "

When La Rochefoucauld-Liancourt, the French aristocrat, reformer and refugee from the French Revolution, visited in 1797, he knew at once what L'Enfant had been reaching for. He studied the major's proposal of broad avenues radiating from meadowed circles and squares, a device apparently borrowed from Pierre Patte's Monuments (1765), and pronounced the plan of "dream-like quality."

The dream was a long time awakening, but suddenly, after more than 150 years of grumbling by European diplomats about the provincialism of the New World capital to which they had been posted, after more than 150 years of invidious comparison to N -- Y -- , the alleged financial and cultural capital of the United States, after more than 150 years of hearing that Washington at its heart is only a small southern town, suddenly, Washington is sophisticated, it is international, it is Paris beyond anything Major L'Enfant ever dreamed of.

SCATTERED up and down 18th Street near Columbia Road and along other streets north of Dupont Circle as well as elsewhere in the city are what are said to be more Ethiopian restaurants than can be found in any other city in the world outside Ethiopia. Injera, tej and doro watt may not yet be household culinary words in these parts, but they are terms comfortably bandied about by many Washingtonians willing to adventure beyond burgers and fries when they're eating out.

Behind the restaurants are a people: the area is home to more natives of Ethiopia than any other African nation except possibly Egypt -- perhaps 1,300, the Bureau of the Census figured in 1980; 5,000 to 10,000, say the Ethiopians themselves, a number that seems more probable, given all those eating places.

Hailemelekot Daniel, 36, the founder and president of the Red Sea Taxicab Association, is one of those immigrants. Seven years ago, five years after he left his homeland for exile in Athens, Daniel arrived in Alexandria with his wife and his daughter Zipporaha, then an infant in arms; the three were sponsored as refugee immigrants by members of the Episcopal Church of the Resurrection in Alexandria, an act of generosity for which Daniel continues to be overwhelmingly and articulately grateful. "When I arrived," says Daniel, "I had nothing." Then he begins to name his sponsors: John Hartigan; the Rev. James Greene, Resurrection's rector; Susan Patterson, who's not a U.S. consular officer in Milan; and more.

An American son, Hanoch, was born to the Daniels, fittingly, the following July 4, but not long thereafter their marriage disintegrated. Taking custody of the two children, Daniel threw himself into work, first as a construction worker, then successively on the staffs of the Crystal City Marriott Hotel and the World Bank. By 1983 he felt ready to launch out on his own. On property on South Capitol Street that he leased from Richard Bell, one of his sponsors, he created the Olympic Taxicab Association. By Daniel's count, more than 100 Olympic cabs now cruise Washington streets, but more visible -- because of the eyesearing Vista Orange hue Daniel paints them -- are the 50-odd cabls of the Red Sea Taxicab Association, a second fleet he started in 1984 and named in honor of the body of water that washes the shores of his native province of Eritrea.

Time was that the taxis of Paris were substantially manned by emigre White Russians and North Africans, and today much of the operation of Washington taxis is similarly nonnative, as anyone can guess from the grumbles of passengers annoyed by English imperfectly spoken and a street pattern imperfectly understood. Daniel sees the drivers of his fleets, most of whom own their own cabs (sometimes on a pay-while-you-work deal that Daniel has staked them to), in a more positive light. "We are 75 percent of us Eritreans and Ethiopians working together in harmony to build new lives," he says. Theharmony contrasts with the political conflict between the Ethiopian central government and its breakaway coastal province that has kept Ethiopia internally at war since 1961.

The remaining quarter of Daniel's drivers comprises native-born Americans and immigrants from Somalia, Iran and Nigeria. The cab companies' bookkeeper, parts manager and "backbone" (as Daniel likes to put it) is Daniel's present wife, Frewayne, who combines her fleet responsibilities with looking after the youngest Daniel, Abel, born last summer. Haile Daniel's family, minus his father and a younger brother who have disappeared, remain in Ethiopia, but Frewayne Daniel's father, mother, two sisters and three brothers have all made their way to the Washington area as refugees. Her father, Wolde Selassie, works close at hand. He's operator of Red Sea Taxicab No. 374.

ANDREW ELLICOTT, the pushy subaltern who soon took L'Enfant's job away from him and signed his own name to the L'Enfant plan, saw no promise to the place where the Eastern Branch, as the Anacostia then was known, joined the Potomac. In a June 1791 letter to his wife, Sally, he groused: "The Country thro' which we are now cutting one of the tenmile lanes is very poor; I think for near seven miles on it there is not one house that has any floor except the earth . . . This country intended for the Permanent Residence of Congress bears no more proportion to the Country about Philadelphia . . . for either wealth or fertility, than a Crane does to a stall-fed Ox . . . " But L'Enfant's appraisal was right, Ellicott's wrong. The city that grew grew wealth; more important, it grew hope as well.

A few blocks away from 18th and Columbia Road, in an office in a made-over house at 3112 Mount Pleasant St. NW, Cristina Martinez answers a ringing telephone: "Carecen, buenas tardes." Martinez, 28, a native of Usulutan, El Salvador, her husband, Jose, and her three children walked from Tijuana, Mexico, into San Diego three years ago, illegally crossing the border, and then flew to Washington to join her sister, who had been living in this area seven years. Although El Salvador (estimated population 4.7 million) is one of the smaller Latin American countries, its natives form what most agree is the area's largest foreign-born group, 70,000, maybe more, the overwhelming preponderance of them without proper papers. (The Bureau of the Census put the area's Salvadorans in 1980 at 4,100, but most observers believe the figure a gross underestimate arising from the difficulty of counting illegal aliens.) The Martinezes can be identified in print, unlike most of the area's Salvadorans, because they are among the fortunate 2 percent of Salvadoran applicants who are granted political asylum by the U.S. Immigration and Naturalization Service.

Cristina Martinez says that economically life was far better for them in El Salvador, where Jose was a professor of philosophy at the university in San Salvador and she was a student in psychology. But when the couple discovered that another man named Jose Martinez was on a right-wing death list and that some people thought that the philosophy professor was the Martinez intended, they decided to flee. In this country, Jose, whose English is shaky, began as an office-cleaner, went on to jobs in construction and as a busboy and now works as a waiter. Cristina started working for Carecen as a receptionist in July 1984. Now she is a paralegal caseworker for the private agency, which assists Salvadorans and other Central Americans legal and illegal.

Martinez yearns for peace to return to El Salvador so she and her family can go home. "I don't want my children to be Americans," she declares, speaking worriedly of how little time she and her husband can spend with their children, working the long hours they do, and how much the Martinez children -- now 9, 7 and 5 -- have already adapted themselves to the surrounding culture.

In the meantime Martinez toils through her days seeking the release of Salvadorans and others who have been arrested by immigration authorities for want of proper documents. By all accounts, only a tiny fraction of the irregular immigrants to the United States, and to the Washington area, ever come to the attention of the authorities. Most reside there, work here, bear citizen-children here, surrounded by sympathetic Americans who can at least guess that these neighbors or co-workers of theirs are in this country without proper permission.

There seems to be little enthusiasm for inquiring into the immigration status of those who are willing to serve as domestics, clean offices at night, bus dirty dishes and wash them in myriad restaurants, work long hours in mom-and-pop grocery and convenience stores.

DANIEL, with his determination to build a prosperous new life, Martinez, with her yearning for home, are only two of tens of thousands of foreign-born people who have poured into the Washington area in the past 25 years, some to build new lives, some to stay "a little while" -- a "while" that often stretches on and on.

There are Afghans and Iranians running shops in Georgetown; Vietnamese launching restaurants and Asian grocery stores along Wilson Boulevard in Arlington; Koreans establishing thmselves as the typical operators of 7-Eleven stores; Jamaicans and Guyanese and Trinidadians arriving on Georgia Avenue with a head start because English is already their language.

How many they may be is only guessable. Of a total 1980 population for the Washington metropolitan area of 3.1 million. the Bureau of the Cenus scounted 250,000 -- 8 percent -- as foreign-born. And no longer, as was once the case, do these immigrants come mainly from Europe. Between 1975 and 1980, according to the census, more immigrants came to the Washington area -- 7,800 -- from Vietnam than any other country. Korea was second with 7,000. But no one knows how many went uncounted, nor how many more have arrived since 1980.

What can be seen, by anyone with open eyes, is how the city has been altered and enriched by their coming. Ethnic restaurants are only the beginning of the story. In season there are West Indians playing their fierce brand of cricket in West Potomac Park. There are Pakistanis transacting business at the National Bank of Pakistan on Connecticut Avenue. There are Iranians discussing the overthrow of the ayatollah at addresses they prefer not to disclose. There is chayote and kimchee and daikon and bitter melon and plaintains and tofu and tomatillos and jicamas for sale at the Safeway.

There is more than can be named. Canopied by trees, linked by broad avenues, refreshed by aprks, nourished by libraries and museums and universities, energized by people of many origins, there grows here a great city far more than the pragmatic seat of government Ellicott assumed was called for. Here, scarcely noticed by many of us, is Paris for our time.