PORTLAND, Ore. — After immigrating to Oregon from the Mexican state of Oaxaca more than two decades ago, Paula Asuncion worked on farms and in minimum wage jobs at fast-food restaurants — a widow struggling to feed six children, sharing cramped apartments with other families.

Her prospects changed two years ago after she joined a program that helps immigrants open small culinary businesses. After training with the microbusiness incubator at Portland nonprofit Hacienda CDC, Asuncion now runs a catering service, employs other immigrants, and has bought a home for her family.

Asuncion’s story is not uncommon. Experts say the economic downturn brought new interest in self-employment from people having a difficult time finding well-paying jobs, and that has spurred significant growth in microbusiness development programs that teach skills such as business plan writing, marketing and accounting.

Interest in opening a business is especially high among immigrants and refugees. Many have low incomes and less access to employment opportunities than the general population because they have limited English language skills, lack reliable transportation or an American diploma, and are still learning how American society works.

Many of them see self-employment as a shot at the “American dream.”

“The biggest concern among immigrants is having stable work. They come to us and say, ‘I want to start a taco stand. How do I do that?’” said Janet Hamada, executive director of Next Door Inc., a social service agency in Hood River, 60 miles east of Portland. The organization plans to expand its business coaching services into a full microbusiness development program aimed at Spanish speakers.

Microbusinesses, defined as enterprises with five or fewer employees, have long been the backdrop of the economy and make up the majority of U.S. businesses. They account for about 26 million jobs in the economy — more than the total number of people employed in local, state and federal governments, according to the Association for Enterprise Opportunity, which provides advice and support for microentrepreneurs.

Though the businesses are tiny — from farmers planting on a few acres, to adult care home owners, to food cart vendors — their impact can be significant, said Marilyn Johnson-Hartzog, executive director of the Oregon Micro Enterprise Network. The newly minted entrepreneurs hire family members and eventually other community members, and their quality of life soars. They spend more money on goods and services and re-invest in the business.

Given a rise in demand for training and coaching for new entrepreneurs, even social service organizations have recently added microbusiness development programs, Johnson-Hartzog said.

In Durham, a new organization called Accion Emprendedora USA aims to help microbusinesses grow in the Hispanic community through training in business planning, marketing and accounting.

Michigan’s Global Detroit initiative is developing a collaborative to provide training, technical assistance, and microloans — very small, short-term loans at low interest — to immigrant entrepreneurs.

In Oregon, Adelante Mujeres — a Forest Grove nonprofit that runs a 10-week small-business course and an agriculture enterprise program for Latinos — has developed a replicable model for training aimed at Spanish speakers and is helping other nonprofits to implement.

Demand for training is especially high among Latinos, partly because some of them lack legal immigration documents, said Adelante Empresas program director Eduardo Corona.

“Anti-immigration laws have led to people having a really hard time finding jobs, even on farms,” Corona said. “Since they have to put food on the table, they’re starting to explore their abilities and thinking of opening a business.”

At Portland’s Immigrant and Refugee Community Organization, known as IRCO, several new microenterprise programs have long waiting lists — including a program that teaches refugees how to start their own home-based childcare businesses.

“The demand is really high,” said program coordinator Tina Do. “A lot of immigrant women come with young children, English language barriers, transportation barriers. It’s really difficult for them to compete with other people out there, even for a minimum wage job.”

When immigrant women start a childcare service, Do said, the benefits spread to other immigrants, who can enter the workforce because they now have childcare near their home.

Asuncion’s catering service in Portland has also spread its benefits to others. The financially struggling farmworker who sold tamales to neighbors has become a full-time entrepreneur who owns Mixteca Catering and runs food stands at four Portland area farmers markets. Asuncion, 54, employs three of her adult children and a nonrelative.

There’s potential for microbusinesses to grow into companies worth billions of dollars. Corporations like Apple, Google and Disney got their start in someone’s garage.

Asuncion credits the Hacienda CDC’s incubator program for teaching her how to sell and advertise to an American public, giving her information on food safety laws, providing access to a commercial kitchen and microloans to purchase equipment, and links to markets and festivals.

Hacienda is expanding on such success by building the Portland Mercado, a market dedicated to small Latino businesses that will include an 11-week course for aspiring entrepreneurs.

“The goal is to show immigrants how to access resources and teach them to do it independently,” said Hacienda’s market coordinator Caitlin Burke.