Red River (1948) on Netflix

By the end of the American Civil War in 1865, Thomas Dunson has managed to carve out his dream of being a cattle rancher in Texas, he having done so largely with the help of an old cowpoke named Nadine Groot, and a young man named Matthew Garth, who Dunson unofficially adopted when he was a boy. This dream has not been without some adversity in his life, such as the situation where he met Matt when the wagon train he and Groot had accompanied for some time from St. Louis in 1951 got ambushed by Indians, with Dunson's love, Fen, one of the victims, and it not being as easy to take over the unoccupied land north of the Rio Grande in west Texas where he eventually established the ranch. The result of the war has left most in the south cash poor, including Dunson, but there being a plenitude of men, ex-soldiers, willing to work as cowboys to rebuild lives for themselves and their families. Despite the potential hazards of the task including the fact that the Indians are still ambushing unsuspecting people, Dunson is able to find a group of men willing to accompany him, Groot and Matt on a potentially lucrative cattle drive to Missouri to sell the close to one thousand head of cattle - which includes some cattle from neighboring ranchers to be sold on consignment - to the companies operating the stockades at the end of the known railroad line. As the drive progresses, Dunson becomes increasingly alienated from the other men, including Matt, for the unyielding ways in his singlemindedness of the task, regardless of anything else. Matt's generally softer stand as opposed to Dunson's "shoot now to kill, ask questions later" mentality Dunson sees as weakness on Matt's part. The two men will have to reconcile their growing adversarial nature against the fact that they truly do love each other as father and son if they are both to survive this drive and beyond, especially as they both live by the code of not standing down from their beliefs.