CHICAGO (AP) _ Jacqueline Jackson was born into poverty, the daughter of migrant workers who survived by picking beans for 15 cents a bushel in Florida.

''I understand the pain of poverty,'' says the wife of Democratic presidential contender Jesse Jackson, another child of the poor South.

''My mother was a dreamer,'' Mrs. Jackson said. ''Therefore, I became bogged down with her dreams and mine. I began to really fantasize. ... I dreamed. There were 1,000 things I wanted to be.''

By the time she was 5, Jackie Jackson had moved with her mother and new stepfather to Newport News, Va., and a better life.

At age 17, she headed north to North Carolina Agricultural & Technical College, where she met her future husband just as the civil rights movement began building momentum.

Through the turbulent years, she has stood with Jackson but rarely by his side, leaving the public with little if any image of her.

On infrequent campaign appearances, Jackson introduces her as ''the chairman of the board.''

But Mrs. Jackson says she intentionally shuns the spotlight and the traditional role of a politician's wife.

''Some of the candidates and their wives will step off the plane together for a picture,'' she told Chicago Times magazine. ''I don't think my husand's candidacy has those needs.''

Jackson has said he was drawn to his wife in college by her interest in foreign affairs and he credits her with helping to spark his interest in international diplomacy.

They met when she was 17. Two years later, they married and eventually moved to Chicago where Jackson launched the civil rights group Operation PUSH, People United To Serve Humanity.

They have five children - two girls and three boys - and Mrs. Jackson concentrated on raising them while her husband helped lead the ongoing civil rights struggle.

She has spent her time primarily as a homemaker in Chicago but a politically active one - pushing her children in strollers along picket lines, helping Jackson set up PUSH, serving as titular head of a family corporation that brought income of $159,000 in income last year.

In recent years, she has pursued her interest in foreign affairs, often traveling abroad.

In January 1985, for instance, she led an 11-member delegation on a tour of drought-stricken Ethiopia. The group met with Ethiopian leaders and toured grisly refugee camps where thousands of people were starving.

''She was extremely capable of representing the country and her husband as a world leader,'' recalled the Rev. Clemson Brown, a New York pastor who went on the trip. ''They afforded us an almost presidential kind of a reception. The respect they gave her was tremendous.''

''She is so small that you expect her to be kind of quiet,'' says Karen Waddles, who also went to Ethiopia. ''But she has a very strong personality. She has a kind of magnetic personality.''

''She's a real goal-oriented person. She kept her eyes focused on our purpose for being there which was to find out what each of us could do in our own circles of influence to help,'' Mrs. Waddles said.

Jackson's Arab-American issues adviser, James Zogby, described Mrs. Jackson as ''intense, brilliant, analytical.'' He said she has good political instincts and is not ''somebody that stands by and smiles pretty while the candidate speaks. She is a woman of substance and a leader.''

''The most exciting thing about a Jackson candidacy is having Jackie as the first lady,'' Zogby said.

Mrs. Jackson, 44, toured war-torn Central America in 1984 with a delegation that denounced U.S. policy there as ''callous'' and ''simplistic.''

She met with world leaders such as Yasser Arafat, Daniel Ortega and Anwar Sadat even before her husband did.

She appeared on NBC's ''Today'' show last June and criticized what she called the news media's glamorous portrayal of Donna Rice whose relationship with Gary Hart led him to drop out of the Democratic presidential race.

When reporters raised the subject of Jackson's fidelity, Jackie Jackson, fiercely protection of her family's privacy, directed the campaign to release a statement that it was ''a matter between the candidate, his family, his conscience and God.''