After 14 years of litigation that included a year of settlement negotiations, Nassau County has agreed to implement a far-reaching affordable housing plan aimed at ending decades of alleged residential segregation between its white communities and communities of color.

The federal lawsuit, launched in 2005 by two progressive organizations represented in part by Hogan Lovells, shifted in recent years toward the goal of settlement after Laura Curran, a newly installed Nassau County executive, looked to alter county housing policy, which the previous administration had resisted, according to a news release issued Friday by plaintiffs and their attorneys.