They came to this country from a miniature melting pot of their own -- the descendants of white Portuguese and black Africans. Theirs is an ethnic tapestry shot through with threads from the Chinese, the Jews, the Moors, the Indians.

For the 300,000 Cape Verdeans in the United States -- nearly as many as in the Cape Verde Islands -- the age-old question of identity is particularly profound.

"My children never knew they were black unitl they went outside the neighborhood," said Donna Cruz, a waitress in the historical waterfront section of this former whaling capital. "The way I was brought up, you'd never say you were black. You were Portuguese. You didn't hang around with Negroes . . . Now we're taught to have pride."

Cruz is a Cape Verdean-American, one of the thousands who emigrated to the United States over the last century to escape the perpetual poverty of their drought-swept island country off the west coast of Africa. They refer to their exodus as the only large-scale "voluntary," or non-slave, emigration from Africa.

Southwest of the waterfront here in the shelter of the stone hurricane wall, an immigrant such as Amelia Pina, who arrived here three weeks ago, finds familiar terrain. It is the "second home" she has read about and seen in photographs all her life.

Stretching along both sides of Akushnet Avenue, about 12,000 Cape Verdeans live in a neighborhood of clapboard and shingle homes and blocks of public housing. Jukeboxes in bars feature Cape Verdean "mornas," or laments of farewell, and women cook a rice-and-bean dish called jagcida or, in American slang, "jag."

Yet so few Americans know about them that when they venture outside their familiar neighborhoods -- here, in Pawtucket, Providence, Boston and a few other places -- as Cruz says: "It's very interesting trying to explain who we are and what we are."

"You might say that the Cape Verdeans are the first example of pure racial democracy," said John (Joli) Gonsalves, a leader of New Bedford's Cape Verdean community.

Some of them joke about being "the green people," after the name of their homeland. Their racial makeup, it seems, confounds not only American social conditioning and bureacratic pigeonholers but also forces Cape Verdeans themselves into odd dilemmas as they face for the first time a system in which people are judged -- to a greater or lesser degree -- by color. s

In keeping with the great paradox of the modern American "melting pot," a contingent of Cape Verdeans traveled from New Bedford to Washington last fall to try to persuade the U.S. Census to give them their own category in the 1980 count. They wanted it based on their ethnic background as Cape Verdeans, not as race.

They won a concession: instructions on the long form only, asking citizens to be specific when they identify their origins and mentioning Cape Verdeans as an example.

But the burden of defining themselves remains with the individual Cape Verdeans.

Along "the avenue," (Akushnet was the name of the whaling ship that carried Herman Melville to sea and helped inspire "Moby Dick"), you can hear many variations, usually in good-natured tones, on their color question.

You hear about Cape Verdeans who, regardless of skin color, consider themselves white and will "hit you with rocks" if you consider them otherwise. You hear of the young Cape Verdean doctor who lives in the suburbs of Boston with his white wife and their children, and who comes home alone to visit his dark-skinned relatives.

You hear about the rising generation of Cape Verdeans, many of whom have taken up the banner of black pride, seeking refuge, as their parents often see it, in an unambiguous identity. "They feel left out; they want to belong somewhere," said one mother.

You hear about the tensions between the new arrivals and the "old guard." The newly arrived immigrants, intent on the economics of survival, are sometimes bewildered by the raised ethnic consciousness of their Americanized countrymen. Other new arrivals are disappointed by Americanized Cape Verdeans who have forgotten their native culture altogether.

Occasional outbreaks of gang violence between young blacks and Cape Verdeans occurred until the '60s focused national attention on civil rights issues. Then things began to change.

"We have a lot of the same problems, a lot of talk about over a beer, you know," said one young Cape Verdean, a plant worker, who said he thinks of himself as an Afro-American.

"Being a Cape Verdean is very, very complex," said Deonilda Rosa, an American-born Cape Verdean who works in the New Bedford office of Rep. Gerry E. Studds (D-Mass.) "You can get a different perception from each person you talk to."

At Alfred J. Gomes Elementary Mary G. Andrade teaches immigrant children who speak Portuguese and their own unwritten dialect Crioulo, about their culture as well as how to speak English as a second language.

She teaches them about both their Portuguese and their black African sides, she said, explaining; "I tell them we come in all colors, hair textures. We all have our own characteristics, our blackness, our whiteness, our in betweeness. . . ."

Anyone asking for unemployment figures or other information learns that Cape Verdeans cause special headaches for local bureaucrats and public officials.

"It's a hell of a mess and there are no simple answers," said William Tansey of the state unemployment compensation office in New Bedford. He ran through a litany of the changing government code system as it might apply to Cape Verdeans: Portuguese/European, black, caucasian, "other than white," and so on.

"I have two Cape Verdeans in my office," he said.

"One has two Cape Verdean parents and calls himself 'nonwhite, minority' and the other has one Cape Verdean parent and one from the Aozres. She calls herself 'white.' But there's hardly any difference in the color of their complexions."

There was a time he sighed, "when 'nonwhite, other' kept everybody happy."

In the days of school desegregation, some recalled the discomfiture of officials who had to go into classrooms and "visually determine" whether their schools were racially balanced.Their difficulties were compounded when some American blacks claimed to be Cape Verdeans.

In the struggle for jobs in the area's factories, fish processing plants and on merchant ships, Costa said, employers tend to lump all black faces together, regardless of what they call themselves.

"Some, such as Polaroid, have good affirmative action programs," he said. "Generally, because of the visibility factor, they see that face and you get the same treatment as any Afro-American, or as a Hispanic . . . It's difficult for any minority to get into a union."

Generally, Costa said, Cape Verdeans share equally with blacks and other low-income Americans the problems of unemployment, youthful drug addiction, low pay and lack of education. And they count under federal minority hiring requirements.

Some employers reportedly prefer to hire Cape Verdeans over Afro-Americans because they consider them "less black" but they still count under minority requirements. And some employers say they prefer Cape Verdeans because they not only count as minorities, but also are bilingual and can help in dealing with the large Portuguese population in New Bedford and nearby areas.

"That fills two holes, and that is an asset, believe me," said John Fielding of the state unemployment office.

Cape Verdeans traditionally have provided a cheap and conscientious source of labor for New England. They were highly regarded (but lowly paid) as harpooners, steersmen and general crewmen on the dangerous and dirty whaling ships of the last century. When that work burned out, they became mainstays in the factories and cranberry bogs on Cape Cod.

Now, with the exodus of industry to the Sun Belt, jobs are scarce in New Bedford. Immigrants must have a guarantee of livelihood before they can come here, so many are heading for more prosperous areas such as Boston, said Joli Gonsalves, coordinator of community development for the mayor's office. Still, New Bedford, by all accounts, remains a mecca for Cape Verdeans in this country.

"Sometimes they find it's hard to get a job, or they work long, hard hours, or they have to be separated from their families, said teacher Virginia Neves Gonsalves (who is no relation to Joli).

"But even after the shocks, this is still the best land, the land where God walked on with his own two feet."

In the immigrant tradition, New Bedford's Cape Verdean community is a chain of families putting down roots and then helping relatives to join them. a

Edward (Fast Eddy) Fortes has worked on the New Bedford docks for 27 years. He is a cutter at the Aiello Brothers fish processing plant.

His hands are scared from occasional side swipes with the filet knife he uses to whittle at high speed on a passing parade of flounder, cod and other species of fish brought in by the Portuguese fishing fleet.

Fast Eddy once cut 86 crates of cod in one day -- a record for the town. He earned a $1 bonus for every box past the first 16, he beamed, chomping on a cigar.

Fortes has welcomed a dozen of his relatives to the United States and helped them get jobs, partly by virtue of his power as a union leader.

He also has put his two daughters through college. One is a school teacher. The other is studying to become "the only Cape Verdean veterinarian in New Bedford," he said proudly.

"We worked hard to get what we got," he said.

The process of starting a new life in the United States begins, for many Cape Verdeans, with an expensive trip from one island to another in the U-shaped archipelago. The U.S. mission is on Praia, but most emigrants are from Brava or Fogo and the waters between the islands are rough. "That alone can cost $300 to $400," an immigration specialist in Studds' office said.

About 1,100 American visas a year, according to State Department figures, are issued in the islands, which became independent from Portugal in 1975. Priority is usually assigned according to how closely related the applicant is to someone in the United States. The wait in the brother/sister category, for instance, is about 14 months.

The immigrants used to come in two-masted schooners or other ships of the packet trade that carried mail, cargo and passengers on often hazardous voyages between New England and Cape Verde (the islanders pronounce Verde to rhyme with bird), some as recently as 1965.

Now they come by air, usually on money borrowed from their families here. Then their first priority is to earn enough to pay it back, the Studds aide said.

Once here, the new immigrants buy homes as fast as they can, by all accounts, often through a two-family arrangement or a consortium of relatives.

Many people who remain behind on the islands live on what is sent them from relatives here, as well as aid from the United States and other countries. Cape Verde, a landscape of volcanic rock and loose soil, is visited regularly by drought. The current one began in 1968.

Because of emigration, Cape Verde is dominated by women and children (half the population is younger than 18) according to a report in the Providence Journal. The fledgling government is exploring for water so that corn and other crops can be cultivated, and is making other moves toward development. But, the report said the process will take at least 20 years.

Amelia Pina, 24, arrived here just three weeks ago from the village of Pai-luis. Her father was already here. One of the first things she did was to start sewing herself a wedding dress.

She had come on what is called a "finacee visa." In a couple of weeks, she will marry an American-born Cape Verdean she met when he was visiting her island.

Joseph J. Alves Jr., her fiance, is a systems programmer for Ford Aerospace in nearby Lexington, Mass. She speaks mostly Crioulo, while he is better, though not fluent, in Portuguese. He's teaching her English.

Pina's only difficulty has been understanding the distances of the American landscape."To her, you can get anywhere in a day, walking or hitching a ride," Alves said. "It was hard to impress on her where Pittsburgh is when I had to go there."

Alves' father, Joe Sr., had come here in 1929 at age 15, and took a job as cook on an oil tanker at $45 a month. He eventually worked his way up to chief steward.

This is a way of life still favored by some young Cape Verdeans men steeped in the seafaring tradition, as Alves was by his whaling grandfather. But Cape Verdeans like to point out that their people are farmers at heart, not seafarers.

In any case, Alves said with a chuckle, "The sons of seamen don't want nothing to do with it. . . ."

"Not my kind of life," said his computer specialist son.

The men are out for months at a time, and although the pay is good (nearly $900 a month for seven months plus a high percentage of full pay for five months off), it gets lonely.

"When you're young, it is a very good life," Alves said. "Fortunately, I marry a girl raised over there and she understood. . . . But when you get old, you realized what you missed, with the kids and all. I have come to realize what my father went through to support the family.