AMC has engineered the priciest original programming deal in its history, spending $15 million for a four-hour miniseries exec produced by and starring Robert Duvall. Duvall and longtime friend Alan Geoffrion developed “Daughters of Joy,” an epic adventure set in the Old West. The story, based on historical documents and research, centers on a rancher, played by Duvall, who crosses paths with five enslaved Chinese women being sent to mining camps to work as prostitutes. The rancher and his nephew take pity on the women and take them along as they transport more than 500 horses from Oregon to Wyoming. Walter Hill, who won an Emmy for directing the pilot episode of “Deadwood,” will helm the project, penned by Geoffrion. Stanley M. Brooks (“Living With the Dead”) and Duvall’s producing partner, Rob Carliner (“The Apostle”), are exec producing.