The film will tell the story of 3 Southern women (2 of them sisters, and the third, a slave) who are forced to defend their home in the last days of the war, against a large group of soldiers who have broken off from the Union Army.
Wilde and Steinfeld will play the sisters, while Beharie will play the slave.
The Keeping Room will be directed by Daniel Barber, from a script written by Julia Hart; financing/producing will be by Wind Dancer Films (the company that also backed What Women Want).
Gilbert Films and Anonymous Content will also produce.
WME Global brokered the deal, at the ongoing American Film Market (AFM), where it's being shopped to international buyers.
Producers call the project "cinematic, thrilling and dangerous," one that is full of "profound themes."
Principal photography is set to begin in March, 2013, in North Carolina.