She eventually was elected president of the local, and her views on Contreras changed: The two married in 1988.
In Los Angeles, Contreras found a city that had been historically hostile to unions. Although by the 1980s, labor had emerged as a key Democratic ally, its participation in local politics was limited.
In 1994, he was tapped as the federation's political director and immediately sought to reshape the unions' role. Contreras applied himself to winning over the often-quarreling local union leaders and insinuating himself into the city's power structure.
At a time when the national labor movement has struggled, Los Angeles' unions have racked up a remarkable number of victories: securing a living wage ordinance in the city, winning substantial wage increases for workers and beating back a state initiative aimed at limiting the collection of union dues for political purposes, among other measures.
Since Contreras was elected secretary-treasurer of the federation in 1996 -- becoming the first nonwhite to win the seat -- the unions' ranks have grown by 125,000 to more than 800,000, an increase fueled mostly by the city's burgeoning Latino immigrant population.
"People across the country look at L.A. as a model of success," said Anna Burger, of the Service Employees International Union.
Despite its growth, the federation's political activism has alarmed some leaders of the area's building trades -- older unions with largely white and African American memberships -- who believe Contreras used the federation to advance the influence of Latinos.
Contreras said that his strategy simply acknowledged demographic realities. "If we're going to grow our union membership in Los Angeles, it's because we're making an outreach to workers that are here," he said.
But he sought to smooth over anxiety by building coalitions with African American pastors and community leaders around issues such as a proposed Wal-Mart in Inglewood. In the last two years, the federation has run successful high-profile campaigns for two African American candidates. Martin Ludlow, a former federation political director, won his race for City Council and Karen Bass won a state Assembly seat.
"I have one desire left, one thing I want to accomplish," Contreras said in an interview earlier this year. "To help take someone to the White House."
Contreras is survived by his wife, a son and a stepson.
Times staff writers Tonya Alanez, Nancy Cleeland, Michael Finnegan and Jessica Garrison contributed to this report.