The movie opens with the wedding of Gilbert and Lana Martin in Albany, New York, in 1776. Gilbert and Lana leave her family's fancy mansion for his much more rustic farm in the vicinity of Deerfield. Lana has some culture shock at first but adjusts to country life and soon is working the farm as hard as Gilbert is.
However, The American Revolution has broken out, and Gilbert has joined a New York militia company. A local Tory, Caldwell (John Carradine) leads his force of Mohawk Indians to the Martin farm, which they burn to the ground. With their farm in ashes, Gil and Lana get jobs working the farm of a local widow. They settle in there, and Lana has a baby.
The war is still raging, and Gil's militia outfit goes off to fight the enemy. Half of them are annihilated at the Battle of Oriskany, but Gil survives and makes it back to Lana. Caldwell leads another, larger British/Indian invasion force in an attack on the valley, and the locals hole up in Fort Herkimer. With ammunition running low, Gil leaves the fort and makes a desperate run for help.
- Badass Preacher: The local parson has no problem picking up a rifle and defending the fort.
- Dawn of the Wild West: All the tropes of The Wild West—determined homesteaders, Indian raids, etc—but happening in upstate New York in the 1770s.
- Determined Homesteader / Determined Homesteader's Wife: Gil and Lana, working their farm in upstate New York. At the end the widow McKlennar leaves her farm to them.
- Determined Widow: Mrs. McKlennar is so intimidating that when the Mohawks come to burn her house, she actually gets them to take her bed downstairs instead of setting it on fire. She also takes part in the climactic battle, suffering a fatal wound in the breast from an arrow.
- Eyepatch of Power: Caldwell, the Tory villain, has an eye patch. After the battle, Blue Duck reveals that he killed Caldwell by showing Caldwell's eye patch.
- Have a Gay Old Time: "That's a queer one, ain't he?"
- Historical-Domain Character: Nicholas Herkimer, a real guy who was mortally wounded at the Battle of Oriskany (although he was really killed by incompetent 1777 medical care).
- Hysterical Woman / Get a Hold of Yourself, Man!: Lana completely loses it after Blue Duck the Mohawk makes an unnecessarily creepy entrance into their cabin late at night. He's friendly, but she is still throwing a fit when Gil slaps her and actually says "You have to get ahold of yourself!".
- Hysterical Woman is averted with Lana after this one episode. She even shoots a Mohawk in the chest.
- It's Quiet... Too Quiet: The men inside the fort actually say this before the final Tory attack.
- Mercy Kill: The Mohawks have captured one of the patriots and are about to light him on fire in front of the fort. The parson shoots him.
- Mildly Military: The hayseeds and old coots in Gil's militia outfit look pretty silly when they are first mustered. However, they later take a level in badass and acquit themselves well at Oriskany and the siege of the fort.
- Thousand-Yard Stare: The parson, wracked with guilt over the Mercy Kill of his friend, has a pretty bad case of this.
- Very Loosely Based on a True Story: The bloody Battle of Oriskany that Gil recounts to Lana really happened, but was not an American victory, at least not in a tactical sense, as nearly half of the American force was killed or wounded and the rest had to retreat. It did however help lead to the lifting of the siege at Fort Stanwix a couple of days later. The climactic battle is loosely based on the 1778 Tory assault on German Flatts, and Adam Helmer's famous run to raise the alarm.
- You No Take Candle: Plenty of this from Blue Duck, the Mohawk who is loyal to America and a friend of Gil.