By July 1863 (Battle of Gettysburg), Winfield Scott had been retired from the army for over a year, stepping down in 1862 in favor of George B. McClellan, who lasted in the position for less than a year. Henry "Brains" Halleck was in that rank in July 1863.
Custer is shown kissing Elizabeth while wearing a Civil War Campaign Medal, first issued on 26 May 1909, with a distinctive two color ribbon (blue and gray, not that it's obvious in a black and white film) first issued 12 August 1913.
During the final battle a trooper struggling with an Indian is shot in the back with an arrow by another Indian. The outline of the square block under his clothes into which the arrow was fired can be clearly seen.
The 7th Cavalry is depicted as being organized at Fort Abraham Lincoln, Dakota Territory. In fact it was organized at Fort Riley, Kansas, and its first campaigns were against the Southern Cheyenne, not the Lakota.
During the First Battle of Bull Run (Manassas) scene, the soldiers are shown riding among rather large hills. The hills appear to be almost barren. The actual battlefield is on gently rolling hills with plenty of flora.
Among the many historical inaccuracies is the fact that Crazy Horse and Custer never met each other face to face. Given Crazy Horse's relative anonymity, it is also unlikely that he would have been recognized had he in fact been captured prior to the Little Big Horn.
Phil Sheridan was not Commandant of West Point during Custer's time there as portrayed in the film. In fact, he was only nine years older than Custer and, having graduated from West Point in 1853, was only a First Lieutenant at the outbreak of the Civil War, not a Colonel.
While the film has Custer offered $10,000 to become President of Sharp's railroad company, the position for which he was actually offered $10,000 in gold (and requested a leave of absence from the Army) was to serve as an Adjutant General in Benito Juarez's army in Mexico.
Numerous times during the film Libbie Custer refers to Gen. Phil Sheridan as "Uncle Phil," a dear friend of her father. In fact there is no evidence that she knew him in any way prior to meeting him through George, although it's possible that she might have come to think of him as family in later years.
Libbie Bacon's father was, as portrayed in the film, against the idea of his daughter marrying Custer, but not because Custer insulted him in a bar. Judge Bacon thought Custer, who was from a humble background, was of insufficient social standing to deserve his daughter's hand. The judge relented only after Custer was promoted in 1864 to the brevet (temporary) rank of Brigadier General.
In the film Custer is awarded a medal. In reality, he never
received any decoration, though he did receive honorary (brevet) promotions for gallantry. The only medal awarded by the government, or the Army, was the newly developed "Medal of Honor", which George Custer never won--though his brother Thomas was one of three soldiers in the Civil War (along with only 16 others since then) to receive it twice.
As Custer meets Libby while walking his "Punishment Tour" at
West Point, he's carrying a Springfield muzzle-loader but the musket has no ramrod, which was essential to its loading. That might be the least of the mistakes in this scene, since history records that Elizabeth "Libbie" Bacon never met Custer while he was at West Point; she met him in 1862, almost a year after he left the academy.
When the Michigan cavalry charges at Gebysyburg they appear to be carrying a 35-star flag (straight rows of 5x7). Use of the 35-star flag went into official effect on 4 July 1863 (following the admission of West Virginia into the Union), which happens to be the day after this scene take place.
Lt. Gen. Winfield Scott (who in reality was no longer in the Army, as noted elsewhere on this page) is handed a message stating "Stuart attacking Hanover", dated 30 June 1863, which is the date Stuart was having his "Ridearound" east of Gettysburg. However, just before receiving the wire, he was discussing with Maj. Taipe his concern about the center of the line at Gettysburg, and that Stuart would "turn the flank at Roundtop". The battle of Gettysburg was started on 1 July, with the battle of Little Roundtop on 2 July.
When at the company trading store talking to Sharp; Custer asks where the Winchester rifles are from that are being sold to the Indians. He is told they are Civil War surplus. The Winchester repeater came out in 1866, the Civil War ended in 1865. Custer also states that they would outrange his carbines. In actuality the reverse is true. The Winchesters were advantageous v the carbines, as repeaters.
"Queens Own Butler" originally introduces the song "Garry Owen" to Custer during the Civil War while in a bar. A couple years later, Custer and his officers meet Butler whereupon Custer tells him he's haunted by the song, but can't remember it. Butler sits down at a piano and plays it for Custer and his officers. Although the officers are hearing the song for the first time, they somehow all know the words and begin to sing along.
In several scenes (as Custer rides into the Black Hills, and later during his charge at the Little Big Horn) the sky as originally shot was apparently later replaced as a visual effect. The clouds are out of sync with the motion of the camera against background hills and the other elements of the shots.
The goof items below may give away important plot points.
Custer tries to get "Queen's Own" Butler out of the final battle on the grounds that he is a foreigner and not an American. If that were true, the 7th Cavalry would have gone into battle without about 40% of its men. Then, as now, joining the US Army was a path to citizenship. Foreigners in the 7th Cavalry were mostly from Ireland, England, and principalities such as Prussia and Bavaria which became Germany in 1871. Other nationalities serving in the 7th Cavalry came from France, Australia, Sweden, Switzerland, Italy, and Hungary.
Numerous inaccuracies regarding the Little Big Horn battle. For example, George Armstrong Custer was most likely one of the first casualties in the battle, not among the last. Since so many facts about this battle were covered up and were only puzzled together as late as the 2000s, the filmmakers in 1941 can be excused for some of this.