Oscar-winner Kevin Costner returns to the director’s chair for the first time since Open Range in 2003 for this sweeping historical drama set during the first half of the 1860s against the backdrop of the Civil War.

“You just gotta keep going,” his weary horse trader growls towards the conclusion of this first chapter of a proposed four-part odyssey.

Horizon: An American Saga – Chapter 1 certainly does keep going, and going, trotting leisurely towards a three-hour running time to…