The big prize that American families came away with in the last, dismal session of Congress was passage of a $22 billion child-care bill to help low-income families get care for their children while they work.

Anyone who had any doubts about the critical necessity of this had only to read the awful story of Chante Fernandez, the 24-year-old single mother from Elizabeth, N.J., who worked five days a week as a secretary but kept her 5-year-old daughter locked in her car on weekends while she worked as a store clerk because she could not afford weekend child care.

Fernandez, who took food to her daughter while she was in the car, pleaded guilty Oct. 26 to a disorderly persons charge and received a $100 fine, which the judge suspended. Her child is to be returned to her by the end of this week. The incident has drawn national attention to the desperate child-care problems of single mothers, in particular.

Amy Wilkins, the program associate for field operations at the Children's Defense Fund, attributed passage of this historic child care bill to political developments that began building in 1988. Because this is one of the few new major pieces of pro-family legislation that's been passed in recent years, what went into its passage bears attention.

"In 1988, the campaign around the bill inside and outside Washington forced child care on the national agenda," she said. "It made its way onto both the Republican and Democratic platforms." That year the child-care bill was killed in the Senate in election-year maneuvering. Nevertheless, Wilkins said, "getting it to the floor reinforced the legitimacy of the issue," as did the swiftness with which it got there.

Then Sen. Orrin Hatch (R-Utah), one of the Senate's staunchest conservatives, made child care his top legislative priority and joined forces with Sen. Christopher Dodd (D-Conn.), the bill's original sponsor. "It established it as more of a bipartisan kind of issue and it no longer could be labeled just a Democratic baby," Wilkins said. She said Hatch was particularly concerned about child-care needs of single mothers.

In the spring of 1989, she said, Senate Majority Leader George Mitchell (D-Maine) "took this issue to heart. He's always been concerned, but then it became a deeper issue for him. He's had wonderful staff support on this issue." When the bill came to the floor, Mitchell offered a substitute that reduced the funding and included tax credits for child care for low-income people. His bill passed, but by the fall, the House was bogged down in a bitter fight over the best way to finance child care.

Marian Wright Edelman, head of the Children's Defense Fund, wrote a fierce and personal memo in November against two members of Congress who were involved in the stalemate. "The memo raised the stakes," said Wilkins. "It said we aren't going to play politics as usual: We care about these kids and we are going to make sure they didn't get chewed up in the legislative process." At one point, the organization and its allies took 300 children to see House Speaker Thomas S. Foley (D-Wash.) and Mitchell.

"It began to make children's issues not fluff issues, not 'feel good' issues, but political issues," Wilkins said.

From the fall of '89 through March 1990, supporters undertook what Wilkins described as a "relentless, grinding process" of haranguing the leadership of the House to bring the bill up. Meanwhile, child-care advocates across the country were writing, phoning and visiting their members. They wrote letters to the editor. An Alabama child-care leader cornered members of Alabama's delegation at an Auburn University football game.

Wilkins traces the strength of the field network back to the Reagan child-care cuts in 1981, which forced states to take up the slack, and taught state advocates networking and lobbying skills they transferred to the federal fight. "The other thing that really mobilized them was the stridency with which" the right wing went after the bill, she said. She said child-care experts in the states had been involved from the start in the bill "and when they would see these crazy letters to the editor that were just fabrications, it got under their skins, and they had the knowledge to refute it."

Finally in April, when the bill went to conference, advocates developed a paper chain that started in San Francisco and came across the country, brought by members of the flight attendants union. When it was stretched from the White House to the Capitol in September it had more than 200,000 links from more than 450 cities, signed by governors and grandparents, mayors and mothers. "The grass-root network was very large," Wilkins said.

But it was also relentless, imaginative and sophisticated. And there is much to be learned from its success.