LAC Executive Director Jennifer Ritter said the organizations, both of which were vocal affordable housing advocates, had been in conversations about merging since the fall, but that members finally voted in support of it on Thursday.
The final details of the consolidation will be clear in about a month, officials with the groups said.
"It's about being more effective in gaining social justice in the neighborhoods," Ritter said. "I think that we can really have a coherent agenda that all of the members are working on together."
Officials with LAC and ONE said the merger would combine the groups' often overlapping advocacy agenda on issues such as health care, mental health, affordable housing, economic justice, violence prevention, education reform and youth issues.
Ritter said the plan was for her to lead the new organization, with ONE's interim director, Angie Lobo, staying on in a role yet to be determined. Lobo, explaining why Ritter would lead rather than her, said that when she took the reins at ONE a couple of years ago, she never intended to keep them.
"We were looking for a new executive director, so we were sort of in a reflective move and thinking about how we could be stronger and what a stronger organization would look like," Lobo said.
Lobo called the new group "a merger of choice and opportunity," and not one of crisis. She said the merger consolidated administrative resources so activists could focus more on organizing.
Aside from volunteers, LAC has about four paid staffers and ONE has at least 12, counting members of violence intervention program Ceasefire who work with the group. Ritter and Lobo said staff levels should remain the same.
LAC and ONE, with about 50 and 100 member institutions, respectively, represent nonprofit organizations, social service agencies, cultural groups, church congregations and school communities, among other entities.
LAC and ONE's relationship with Ald. James Cappleman (46th), whose ward includes most of Uptown and parts of Lakeview, has been described as "strained" by activists, who say he is reluctant to work with them on issues in his ward affecting vulnerable populations.
Both groups have criticized Cappleman for policies that allegedly cater to real estate developers, upper-middle class people and property owners at the expense of poor and working class folk.
The alderman's office has expressed frustration with ONE and LAC because both groups tend to launch protests in Uptown and Lakeview when conversations about affordable housing issues don't go their way.
The last big dustup between Cappleman and activists was at the the end of March, after Cappleman decided to skip a meeting with activists and residents because of a scheduling conflict and the lack of a venue for the meeting.
Activists accused Cappleman of intimidating officials at the People's Church, which had been the scheduled location for the meeting before officials there (who later sought Cappleman's support for a crucial zoning change) backed out citing disapproval of ONE's tactics — and unease with being "labeled as being an enemy of the alderman."
In response to the botched meeting, the groups protested outside Cappleman's office — and his Uptown condominium — and held a mock "funeral for diversity in the 46th Ward," (complete with a presumably empty coffin and pall bearers).
Lobo has her doubts that the alderman's office always considers the group's concerns "in good faith."
"We don't go to those tactics, marches and protests and press conferences, without first trying every other option," she said.
Cappleman's office declined to comment.