Actors Morgan Freeman and Anthony Edwards have joined the cast of a new play based on the trial over the constitutionality of California's gay marriage ban, Proposition 8.

The 13-day trial, held last year in San Francisco, resulted in Judge Vaughn Walker, now retired, declaring the 2008 voter-approved amendment unconstitutional. Proponents of the ban appealed the ruling, and gay and lesbian couples in California remain banned from marrying.

Milk scribe Dustin Lance Black penned the play, which is simply titled 8 and is based the trial transcripts and interviews. Black told The New York Times that the play was six months in the making.

“I mined the best arguments on both sides, trying to capture everything on their side that was a winning point and anything on our side that was a winning point,” he said.

Freeman and Edwards have agreed to a one-time staged reading on Broadway to benefit The American Foundation for Equal Rights, the group formed specifically to challenge Proposition 8. The Monday, September 19 performance at the Eugene O'Neil Theatre will also co-star Cheyenne Jackson, Christine Lahti, Rob Reiner, Yeardley Smith and Marisa Tomei. Tony Award-winning actor and director Joe Mantello will direct the play's premiere.

Subsequent productions are planned at Carnegie Mellon University, Northwest, and the University of Michigan.

Tickets begin at $500.