I concur with those that believe 1873 Winchesters (maybe even Spencers, although less reliable and of lower power- he had used them effectively at the Battle of Yellow Tavern) would have made the difference.
Some other observations on issues raised by others:
Disclaimer: Not a Custer "fan", just an advocate of treating historical personages with the consideration I would like to receive myself.
IMO Graduating last in your class from West Point in 1861, the curriculum of which largely centered on mathmatics, engineering, and classical languages, probably required greater intelligence and self-discipline than being first in your class in most of today's four year institutions.
Just graduating a college put you in the top 2% of the population.
A number of pretty sharp general officers of the era who worked with him, including Phil Kearny (Columbia U.), W'm. Smith (4th in his class), McClellan (2nd in his class), Alfred Pleasanton (7th in his class), Sherman (6th in his class), Sheridan (34th in his class), had a high regard for his abilities. He defeated J.E.B. Stuart, no slouch as a cavalry commander himself, at Yellow Tavern -ok, ok, so Sheridan had four brigades, of which Custer's was one vs Stuart's two-
. [At the battle of Antietam, while Burnside (18th in his class) dithered over funneling his command across a single bridge, it was Custer that finally rode into the middle of the creek to show its depth.] Custer's rashness, audacity, fearlessness and a drive for glory served him well, and were characteristics generally admired by Americans in that era.
They led to friction in the drastically reduced postCW army where a man could languish in a rank for 20 years before promotion. He generally was not popular in frontier service, due in part to the perception that he had abandoned a Lt. Elliot and 19 men who became separated during action against Black Kettle of the Cheyenne and Kiowa at the Wa****a . (Interesting parallel with the Little Big Horn in that Custer refused to believe reports on the size of the Indian encampment here as well, but it was Elliot and his men that were cut off and rubbed out). [Perhaps he took the role of Elliot at the Big Horn in part to vindicate his action on the Wa****a. But in any event, he did not apply the lesson of that action, most likely he viewed it as an aberation.]
While his Congressional testimony about corruption in the Grant administration's Indian Bureau is seen by some historians as political opportunism, he also had a genuine concern for better treatment of reservation and treaty Indians which would benefit both Indians, pioneers and the military in frontier service.
Wish I remembered the details better, but a number of years (10-15) ago some group (USA War College?) gave the Little Bighorn to a number of army officers who were combat veterans as an exercise. They provided them with the context and the same orders and intell in the same sequence that Custer would have received them. IIRC these men made basically the same decisions that Custer had.
(How come a legitimate geographical place name gets asterisks in place of four letters right in the middle of it? You folks from Kansas should be insulted that they think you live in the vicinity of an obscenity. ;-) )
