It’s difficult to believe that so many prominent actors (both in front of and behind the camera) could be brought together for this sweeping story about the spirit of early American settlers. From the very beginning, Alfred Newman's music signals that something substantial is coming – and visually, it doesn't disappoint. The narrative unfolds as a series of connected events, showing three periods in the lives of families moving west, who face nearly every conceivable hardship as they deal with the gold rush, the construction of railroads (and those who preyed on them!), interactions with Native Americans, the Civil War – and the unforgiving landscape itself—all testing even the most resilient people. Debbie Reynolds offers some early entertainment around a campfire with an energetic performance of Sammy Cahn's "Home in the Meadow," which establishes the tone as they travel through the wilderness. It would be simpler to name those who weren’t involved than those who are, but Karl Malden and Jimmy Stewart give memorable performances at the start of their journey; George Peppard has a certain intensity about him, Henry Fonda plays “Jethro”—and Richard Widmark also contributes as the tough railroad man "King." The passage of time isn't always convincing; the obvious application of gray hair dye to Reynolds and Peppard seems unnecessary—we can easily imagine the years passing without it. The script is generally strong, guided by a consistent vision (despite having three directors and multiple cinematographers), with frequently clever and realistic dialogue delivered effectively by the large cast. It runs for nearly three hours, but the story moves along at a good pace, carrying us through their adventures, romances, losses, and sheer determination. Spencer Tracy’s narration occasionally veers into overly sentimental territory, particularly in the ending, but if you're fond of westerns, it’s hard to find something better than this.

Source on TMDB