Born on 15 November 1834, in Carrollton, Illinois, Reno entered West Point Military Academy on 1 September 1851. It took him almost six years to graduate, mostly due to acquiring demerits for being tardy. Reno ranked 20th in a class of 38, graduating in June 1857.
Reno commanded the 7th Cavalry during Custer's absence through the winter and early spring of 1876. During this time the full regiment was brought together for the planned campaign against the Lakota and Cheyenne south of the Yellowstone River in southeastern Montana. Custer returned to Fort Abraham Lincoln in early May. Major Reno was second in command of the 7th Cavalry as part of the Dakota Column headed by General Alfred Terry which left the fort on May 17, 1876.
Major Reno led the scouting efforts with six companies of the 7th from June 10-19. Discovering that the large Indian village had moved from the Rosebud River west to the Bighorn valley, the 7th Cavalry left the Yellowstone River on June 22. This was part of a pincers movement against the American Indian village.
Role in the Battle
On June 25, Custer's Crow scouts located the village of Lakota and Cheyenne people, estimated today at over 8,000 individuals. As the 7th Cavalry approached the Little Bighorn River, Reno was directed to take three companies and cross the river and attack the village from the south. At that time Custer told Reno he would support him with the "whole outfit." As Reno approached the village hundreds of warriors responded to meet him. Reno called a halt, had his men dismount and form into a skirmish line. After a short time Reno's skirmish line was flanked and he fell back to the woods along the river.
For a time Reno's battalion held out in the woods as the Indian warriors surrounded the soldiers. When the Lakotas and Cheyennes fighting him began to infiltrate the woods, Reno decided his defensive position was untenable. At that time Arikara scout Bloody Knife was shot in the head while Reno tried to communicate with him. Reno mounted his troops and led them in a headlong charge that became a retreat and then a mad run for life to the bluffs across the river. Some men from Company G were left in the woods; those that left late were killed, those that stayed in the woods eventually made it back to Reno's defensive position across the river.
Soon the Indian defenders left Reno's front to respond to Custer's threat further down river. Shortly before this Captain Benteen's battalion of three companies arrived at Reno's position in response to Custer's comminque. Reno rushed out to Benteen and said, "For God's sake, Benteen, halt your command and help me! I've lost half my men!" In the meantime firing was heard down river and Captain Weir sought Reno's permission to move Company D towards the sound of the firing. Eventually the pack train came up and with the wounded Reno attempted to move the command to follow Weir.
The Lakota and Cheyenne warriors responded to the soldiers' appearance on the high ground to the south and forced Reno back to his original position on the bluffs. Into the next day (June 26) the remainder of the 7th Cavalry commanded by Reno and Benteen held out under heavy fire from the Indian warriors. With the approach of General Terry's column, the warriors broke off the siege of Reno's position and the great village moved off to the south. Reno's men learned of Custer's fate from Terry's column on June 27.
Ramifications of the Battle
After learning the fate of Custer's battalion, the men under Reno's command were grateful for their survival. However, in a short time following the battle Reno came under considerable criticism from disparate elements both within and outside the army. Reno was accused of not prosecuting the attack on the village as ordered and of not coming to Custer's support.
Though Reno's actions at the Little Bighorn were never officially criticized by the army command, he called for a Court of Inquiry into his actions at the battle to officially exonerate his name. On February 10, 1879, after extensive interrogation of the officers and civilians present at the battle, the court concluded the following:
"…while subordinates in some instances did more for the safety of the command by brilliant displays of courage than did Major Reno, there is nothing in his conduct which required [adverse criticism] from the Court."
Ultimately, the criticism of his conduct at Little Bighorn was only one element which conspired to end Reno's military career. After the loss of his wife in 1874, Reno descended into alcoholism. Altercations with fellow officers and inappropirate advances towards women initially resulted in a two year suspension from the army. He was eventually dismissed from the army, effective 1 April 1880.
Marcus Reno unsuccessfully sought reinstatement into the army for many years. He died as a result of mouth cancer on 30 March 1889.