Custer's Last Stand during The Battle of the Little Bighorn has been subject to acres and acres of print analysis, archeology and Sunday morning quarterbacking.
Frankly the information we got is still woefully incomplete but here are a couple of things to keep in mind.
1, The Army and Custer was very worried about the Indians running away and dispersing. The idea that the Indians would stand and fight a pitched battle was not something Custer and Gibbon gave a lot of thought to.
Thus Custer's plan of battle was designed to capture the Indians, or as many has possible, before they got away. Hence Custer dividing up his command, basically in order to help close off escape routes.
2. A few days before the Battle of the Little Bighorn. The Indians had attacked Crook at the Battle of the Rosebud. This day long engagement had been tactically indecisive, although the Indians eventually withdrew. Crook was so shaken that he retreated after the battle. Crook had c. 1,000 soldiers and c. 200 Indian scouts and he had narrowly avoided a serious tactical defeat. For years it had been assumed that the Indians ha hugely outnumbered Crook, (2,000 - 4,000 warriors.). This now appears to be wrong. More likely it was the Indians who were outnumbered. (c. 750-1,000). It appears that Indian leadership was very good in this engagement. (Crazy Horse for example).
Basically the Indians were primed for a showdown with the Army. Crazy Horse was angling for the Indians to fight something like set piece battles and Sitting Bull had just gone through the Sun Dance ceremony in which he had had a vision of Soldiers falling in camp and thus a great victory. The Indians were psychologically set up for a battle and victory. Custer and Gibbon had no idea of the temperament of the Indians they were seeking and they were not aware of the military consequences of such a temperament, i.e., the Battle of the Rosebud, which indicated that the Indians would stand and fight and fight hard.
3. Custer's apparent plan makes sense if we accept that from his point of view the problem was getting at the Indians before they got away. If the Indians stood and fought it would in all likelihood become unglued. And Custer was not aware that the Indians would in fact stand and fight.
4. Indian numbers in the battle. There is a very long and interminable debate about the size of the Indian village at the Little Bighorn. It appears that previous figures that give a huge size to the village are dubious and figures of 5,000 warriors are gross exaggerations. In fact I t appears that the upper limit to the number of warriors present is probably 3,000. Although these days figures of 1,500-2,000 are given more frequently and even figures of under 1,000.
5. Regardless of the figures it appears that c. 200 Indian warriors had rifles that were superior to the carbines that Custer's troops had.
6. Reno apparently thought that Custer was going to attack in concert with him. And when Custer for whatever reason apparently did not felt betrayed and left to twist in the wind.
7. If the Indian warrior numbers were anything like 3,000 than Benteen and Reno going to rescue Custer would have been a fools errand. It only makes sense has a practical move if we significantly downgrade Indian numbers. Otherwise it would have been suicide. If such was the case then Benteen's caution was sensible if non heroic.
If Indian numbers were far less than Benteen and Reno's refusal to move en-mass, (I should point out they could not have moved their entire united command, some men, at least 100 would have been left behind.), doomed Custer's command to complete extinction.
8. Custer's command was probably obliterated in a very short period of time probably well under an hour. The odds against them were too great. So the window of opportunity to save some of Custer's men was probably brief.
9. Given Custer's tactics which were based on a misreading of the Indians intentions, temperament and leadership. Given the likely number of actual Indian warriors, (Probably 1,500-2,000), a serious defeat was all too likely. Custer and his associates had committed one of the most serious mistakes a military commander can make. They had misread their opponents and had adopted a strategy based on that misreading that played directly into their enemies hands.
10. The fact that Indian losses were far less than Custer and his command's is proof of the actual odds against Custer. The best available evidence indicates that at most 60 Indians died in the battle or of wounds later on and this includes c. 10 women and children. And it likely that this figure is too high and the actual figure is c. 30-40 warriors. Whereas c. 250 men of the seventh cavalry died. This doesn't include the dead Indian scouts.
11. the siege of Benteen and Reno's troops do not give a good indication of whether or not if they had united with the remnant of Custer's command they would have been able hold the Indians off because it appears that the attacks on Benteen and Reno by the Indians were not serious or in fact meant seriously on the part of the Indians.
It was a pretty one sided victory for the Indians. And it appears that has few has 14 Indians may have died in the actual Custer's Last Stand battle has against c.200 of in the command surrounding Custer that was completely whipped out.
In conclusion I think that the recent suggestion that Custer's plan involved something similar to what he had done at the Washita in 1868, i.e., capture Indian noncombatants and thus prevent the Indians from running away and forcing them to back off, was something like he was planning to do. Sadly for him it didn't work and instead of running away the Indians were determined and closed in on him. It appears that the Indians, Crazy Horse in particular, after repulsing Reno deliberately concentrated against Custer's command and destroyed it. It was not the way Custer et al were expecting the Indians to behave.
As for Reno and Benteen. While it is true that if Indian warrior numbers were c. 3,000 then going to Custer's assistance would have been suicidal, although if Indian numbers were significantly less, had they done so they might have been able to rescue some of Custer's men. But sadly I agree that personal animus played a role in it. Benteen deeply resented the fact Custer had at the Washita in 1868 left a group of c. 35 men behind and all 35 had been killed. Reno also didn't like Custer. All of this probably helped to them to decide to leave Custer to stew in his own juices. And has such significantly damages their professional reputation.
As indicated above it is debatable weather or not Reno and Benteen could have saved Custer's command or much of it at all or if they would have been cut up also. It all depends on Indian numbers. It does seem to be the case that by the time Weir started out Custer's command was almost entirely if not completely destroyed. But of course how long the destruction of Custer's command is subject to conflicting debates. It does appear that most Indian accounts talk about a short battle of less than an hour and some as little has 20 minutes.
As for who was responsible for the disaster at the Little Bighorn. Well I would give credit to Sitting Bull, Crazy Horse, Gall and the Indians who took full advantage of the "mistakes" of Custer et al to score a signal victory. I would agree that Reno and Benteen likely left Custer in the lurch for less than credible personal reasons. Whether this in the end this had any practical effect is subject to debate.
