Goofs

In the battle scene inside the fort where Pembroke and his men are throwing bundles of dynamite, the same structure is show blowing up several times from several different angles. Each is shown to be a separate structure.

In the battle scene inside the fort, several Confederate soldiers are running up a stone staircase up the wall. Several of the men get gunned down by the Gatling gun. However, after the sound of the Gatling gun stops, a final man running up the stairs throws his hands in the air, as if he was shot and falls dead. This could have been from another gunshot, but the implication was that it was from the Gatling gun.

The film is set in 1862 but features Gatling guns that, presumably, formed part of the fort's arsenal when it was in Union hands.The gun was designed by Dr Richard J Gatling in 1861 and patented on November 4, 1862. Though two examples were employed near Petersburg and eight fitted on gunboats, it was not accepted by the American Army until 1866. So it's most improbable that it would have been available in a remote theatre of the Civil War.

Car tyre marks clearly visible in the dust as the group ride away from the hanging in the early part of the movie.

At the end of Telly Savalas' first scene he lights up a modern cigarette which clearly has a filter.

The one-armed sheriff who arrests Ted for looting is using a revolver with a long 'Buntline' barrel. The movie is set and 1862, but there is no evidence this style of barrel was manufactured prior to 1876.

The story is supposed to be set in 1862, but soldiers are shown using dynamite, which Alfred Nobel patented in 1867.