Rachel Griffiths, Mary-Louise Parker and Guy Pearce are set for lead roles in ABC's upcoming miniseries about the gay rights movement.

The eight-hour miniseries, titled When We Rise, has been in development at ABC for more than two years.

According to Deadline Hollywood, Pearce (The Adventures of Priscilla: Queen of the Desert, LA Confidential) will play activist Cleve Jones, while Parker (Weeds, Angels in America) has been cast to play Roma Guy, a leader of the womens rights movement. Guy's wife, activist Diane, will be portrayed by Griffiths (Brothers & Sisters, Six Feet Under).

(Related: Carrie Preston to star in gay rights miniseries When We Rise.)

The project reunites the team behind the 2008 film Milk: Director Gus Van Sant, writer Dustin Lance Black and producer Bruce Cohen. Milk's subject was Harvey Milk, an LGBT rights activist and politician who was gunned down inside San Francisco City Hall. Van Sant is set to direct the first two-hour episode of When We Rise and will co-produce the series with Black, Cohen and Laurence Mark.