Birth and family
Custer was born in New Rumley, Ohio, to Emanuel Henry Custer (1806-1892), a farmer and blacksmith, and Marie Ward Kirkpatrick (1807-1882). Through his life Custer was known by a variety of nicknames: Armstrong, Autie (his early attempt to pronounce his middle name), Fanny, Curley, Yellow Hair, and Son of the Morning Star. His brothers Thomas Custer and Boston Custer died with him at the Battle of the Little Big Horn, as did his brother-in-law and nephew; his other two full siblings were Nevin and Margaret Custer; there were several other half siblings. Custer's father's family originally came from Westphalia in Northern Germany. They emigrated and arrived in America in the 17th century. The original family name was "Küster".

Custer's mother's original maiden name was Marie Ward. In 1823 she married Israel Kirkpatrick who died in 1835. Being a widow, she then married Emanuel Henry Custer in 1836. Marie Ward's grandparents George Ward (1724-1811) and Mary Ward (nee Grier) (1733-1811) were born in the County of Durham in Northern England and emigrated to the United States. Their son James Grier Ward (1765-1824) was born in Dauphin, Pennsylvania and married Catherine Rogers (1776-1829), and their daughter, Marie Ward, was Custer's mother. Catherine Rogers was the daughter of Thomas Rogers (born in England in 1742) and Sarah Armstrong, which is the source of George Armstrong Custer's middle name.

Early life
Custer spent much of his boyhood living with his half-sister and his brother-in-law in Monroe, Michigan, where he attended school and is now honored by a statue in the center of town. Before entering the United States Military Academy, he taught school in Ohio. A local legend suggests that Custer obtained his appointment to the Academy due to the influence of a prominent resident, who wished to keep Custer away from his daughter.

Custer graduated from West Point, last of a class of 34 cadets, in 1861, just after the start of the Civil War. His tenure at the academy was a rocky one and he came close to expulsion each of his four years due to excessive demerits, many from pulling pranks on fellow cadets. But he began a path to a distinguished war record, one that has been overshadowed in history by his role and fate in the Indian Wars.

Civil War
McClellan and Pleasonton
Custer was commissioned a second lieutenant in the 2nd U.S. Cavalry and immediately joined his regiment at the First Battle of Bull Run, where Army commander Winfield Scott detailed him to carry messages to Major General Irvin McDowell. After the battle he was reassigned to the 5th U.S. Cavalry, with which he served through the early days of the Peninsula Campaign in 1862. During the pursuit of Confederate General Joseph E. Johnston up the Peninsula, on May 24, 1862, Custer persuaded a colonel to allow him to lead an attack with four companies of Michigan infantry across the Chickahominy River above New Bridge. The attack was successful, capturing 50 Confederates.

Major General George B. McClellan, commander of the Army of the Potomac, termed it a "very gallant affair", congratulated Custer personally, and brought him onto his staff as an aide-de-camp with the temporary rank of captain. In this role, Custer began his lifelong pursuit of publicity. On one occasion when McClellan and his staff were reconnoitering a potential crossing point on the Chickahominy River, they stopped and Custer overheard his commander mutter to himself, "I wish I knew how deep it is." Custer dashed forward on his horse out to the middle of the river and turned to the astonished officers of the staff and shouted triumphantly, "That's how deep it is, General!"

When McClellan was relieved of command in November 1862, Custer reverted to the rank of first lieutenant. Custer fell into the orbit of Maj. Gen. Alfred Pleasonton, who was commanding a cavalry division. The general was Custer's introduction to the world of extravagant uniforms and political maneuvering and the young lieutenant became his protégé, serving on Pleasonton's staff while continuing his assignment with his regiment. Custer was quoted as saying that "no father could love his son more than General Pleasonton loves me."

After the Battle of Chancellorsville, Pleasonton became the commander of the Cavalry Corps of the Army of the Potomac and his first assignment was to locate the army of Robert E. Lee, moving north through the Shenandoah Valley in the beginning of the Gettysburg Campaign. Custer distinguished himself by fearless, aggressive actions in some of the numerous cavalry engagements that started off the campaign, including Brandy Station and Aldie.

Brigade command and Gettysburg
Three days prior to the Battle of Gettysburg, General Meade promoted Custer from first lieutenant to brevet brigadier general (temporary rank) of volunteers. Despite having no direct command experience, he became one of the youngest generals in the Union Army at age 23.

Two captains—Wesley Merritt and Elon J. Farnsworth—received the same promotion along with Custer, although they did have command experience. Custer lost no time in implanting his aggressive character on his brigade, part of the division of Brig. Gen. Judson Kilpatrick. He fought against the Confederate cavalry of J.E.B. Stuart at Hanover and Hunterstown, on the way to the main event at Gettysburg.

Custer's style of battle sometimes bordered on reckless or foolhardy. He often impulsively gathered up whatever cavalrymen he could find in his vicinity and led them personally in bold assaults directly into enemy positions. One of his greatest attributes during the Civil War was luck and he needed it to survive some of these charges. At Hunterstown, in an ill-considered charge ordered by Kilpatrick (but one that Custer did not protest) against the brigade of Wade Hampton, Custer fell from his wounded horse directly before the enemy and became the target of numerous enemy rifles. He was rescued by the bugler of the 1st Michigan Cavalry, Norville Churchill, who galloped up, shot Custer's nearest assailant, and allowed Custer to mount behind him for a dash to safety.

Possibly Custer's finest hour in the Civil War was just east of Gettysburg on July 3, 1863. In conjunction with Pickett's Charge to the west, Robert E. Lee dispatched Stuart's cavalry on a mission into the rear of the Union Army. Custer encountered the Union cavalry division of David McM. Gregg, directly in the path of Stuart's horsemen. He convinced Gregg to allow him to stay and fight, while his own division was stationed to the south out of the action. At East Cavalry Field, hours of charges and hand-to-hand combat ensued. Custer led a mounted charge of the 1st Michigan Cavalry, breaking the back of the Confederate assault, foiling Lee's plan. Custer's brigade lost 257 men at Gettysburg, the highest loss of any Union cavalry brigade.

Marriage
He married Elizabeth Clift Bacon (1842–1933) on February 9, 1864. She was born in Monroe, Michigan, to Daniel Stanton Bacon and Eleanor Sophia Page. They had no children.

The Valley and Appomattox
When the cavalry corps of the Army of the Potomac was reorganized under Philip Sheridan in 1864, Custer retained his command, and took part in the various actions of the cavalry in the Overland Campaign, including the Battle of the Wilderness (after which he ascended to division command), the Battle of Yellow Tavern, where Jeb Stuart was mortally wounded, and the Battle of Trevilian Station, where Custer was humiliated by having his division trains overrun and his personal baggage captured by the Confederates. When Confederate General Jubal A. Early moved down the Shenandoah Valley and threatened Washington, D.C., Custer's division was dispatched along with Sheridan to the Valley Campaigns of 1864. They pursued the Confederates at Winchester and effectively destroyed Early's army during Sheridan's counterattack at Cedar Creek.

Custer and Sheridan, having defeated Early, returned to the main Union Army lines at the Siege of Petersburg, where they spent the winter. In April 1865 the Confederate lines were finally broken and Robert E. Lee began his retreat to Appomattox Court House, pursued mercilessly by the Union cavalry. Custer distinguished himself by his actions at Waynesboro, Dinwiddie Court House, and Five Forks. His division blocked Lee's retreat on its final day and received the first flag of truce from the Confederate force. Custer was present at the surrender at Appomattox Court House and the table upon which the surrender was signed was presented to him as a gift for his gallantry. Before the close of the war Custer received brevet promotions to brigadier and major general in the Regular Army and major general in the volunteers. As with most wartime promotions, these senior ranks were only temporary.

Indian Wars
In 1866, Custer was mustered out of the volunteer service, reduced to the rank of captain in the regular army. At the request of Maj. Gen. Phillip H. Sheridan, a bill was introduced into congress to promote Custer to major general, but the bill failed miserably. Custer was offered command of the 10th U.S. Cavalry (otherwise known as the Buffalo Soldiers) with the rank of full colonel, but turned the command down in favor of a lieutenant colonelcy of the 7th U.S. Cavalry and was assigned to that unit at Fort Riley, Kansas.

His career took a brief detour in 1867 when he was court-martialed at Fort Leavenworth, Kansas, for being AWOL. Abandoning post to return to his wife, along with 10 other soldiers and suspended for one year (staying with his wife for the year at Fort Leavenworth), returning to the Army in 1868. He took part in General Winfield Scott Hancock's expedition against the Cheyenne. Marching from Fort Supply, Indian Territory, he successfully attacked an encampment of Cheyennes and Arapahos (of 150 warriors and some 50 civilians and 6 white hostages) - the Battle of Washita River on November 27, 1868.

This was regarded as the first substantial U.S. victory in the Indian Wars and a significant portion to the southern branch of the Cheyenne Nation was forced onto a U.S. appointed reservation. Three white prisoners (two boys and a woman called Miss Crockers) were freed during the encounter, and the others (a woman and two little boys) were killed by their Cheyenne captors. More than 120 warriors were killed along with less than 20 civilians. The deaths of these civilians, however, infuriated some humanists in the East.

Historian Jerome Greene wrote in 2004 that the Battle of the Washita could not be considered a massacre at all, because "the soldiers evidently took measures to protect women and children". In 1873, he was sent to the Dakota Territory to protect a railroad survey party against the Sioux. On August 4, 1873, near the Tongue River, Custer and the 7th U.S. Cavalry clashed for the first time with the Sioux. Only one man on each side was killed.

In 1874, Custer led an expedition into the Black Hills and announced the discovery of gold on French Creek near present-day Custer, South Dakota. Custer's announcement triggered the Black Hills Gold Rush and gave rise to the lawless town of Deadwood, South Dakota. In 1875, Custer swore by White Buffalo Calf Pipe, a pipe sacred to the Lakota, that he would not fight Native Americans again.

Battle of the Little Bighorn
In 1876, Hiester Clymer, Chairman of the House Committee on Military Expenditures, commenced an investigation of various acts of Secretary of War William W. Belknap. Custer was called to testify in the proceedings, despite his statement that what he knew was only by hearsay. But his testimony seemed to confirm the accusations not only against Belknap, but also against President Ulysses S. Grant's brother Orville Grant. The president ordered Custer placed under arrest. This delayed a scheduled expedition against members of the Lakota, Northern Cheyenne and Arapaho Nations who resisted being confined to their designated reservations, in which Custer was to be involved. Grant relieved Custer of command and ordered the expedition to proceed without him. Custer wrote to the president:

Custer knew he was outnumbered, though he did not know by how much (probably something on the order of 3 to 1). Despite that knowledge he split his forces into 3 battalions: one led by Major Marcus Reno, one by Captain Frederick Benteen, and one by himself (this actually split his forces into 4 parts as Capt. Thomas M McDougall and Company B were with the pack train). Reno was ordered to attack from south of the village, while Benteen was ordered to go west, scouting for warriors or the Indian village, while Custer himself went north, in what was intended to be a classical pincer movement.

But Reno’s attack failed and he engaged in a disorganized retreat causing the loss of a quarter of his command. Meanwhile, Custer located the encampment. Recent evidence suggests that Custer was trying to capture some of the fleeing non combatants, replicating a similar action eight years earlier, when the taking of women and children hostage had forced the Indians back onto their reservation. When Custer saw the immense size of the village he sent a second message to the rear: "Benteen, come on, big village, be quick, bring packs, p.s. bring packs!".

Benteen was already on his way back when he halted to help Reno in a defensive position on the bluffs. Many of the Indians that had been facing Reno were freed by his retreat, and were now able to concentrate on Custer's battalion. It is believed at this point that Custer attempted a diversionary attack on the flank of the village, deploying other companies on the ridges in order to give Benteen the time to join him. But Benteen never came and so the company trying to ford the river retreated to higher ground.

After a lengthy defensive fight, groups of warriors made encircling and penetrating attacks so that the cavalry companies on the hills eventually collapsed and fell back together on what is now called "Custer Hill". There, the survivors of the command exchanged fire with the the Indians and fell to the last man. The Indian assault was both merciless and tactically expected. Without the support of Benteen's battalian, the Sioux Indians outnumbered Custer's command by nearly 10 to 1. When the Indians realized their superior numbers, they closed in for the final attack and killed all to the last man. As a result, the Battle of the Little Bighorn has come to be popularly known as 'Custer's Last Stand'.

Custer was said by some historians to be killed while attempting to cross the river, but the shell casings found under his body suggest otherwise. Many of the corpses were stripped, scalped, and mutilated; some having their skulls crushed. Custer’s body had two bullet holes, one in the left temple and one just above the heart. His body was stripped but not mutilated; there were some superficial wounds probably not mentioned by those who found him. Early reports attributed this to the respect the Indians had for his valor but it is doubtful he was recognized as he was dressed in buckskins and his “long Hair” was cut short before the battle. Others claim his body was protected by the Cheyenne, who recognized him from his earlier campaigns against them at the Battle of the Washita.

Following the recovery of Custer's body, he was given a funeral with full military honors. He was buried on the battlefield, which was designated a National Cemetery in 1876, but was reinterred to the West Point Cemetery on October 10, 1877.

Controversial legacy
After his death, Custer achieved the lasting fame that eluded him in life. The public saw him as a tragic military hero and gentleman who sacrificed his life for his country. Custer's wife, Elizabeth, who accompanied him in many of his frontier expeditions, did much to advance this view with the publication of several books about her late husband: Boots and Saddles, Life with General Custer in Dakota (1885), Tenting on the Plains (1887), and Following the Guidon (1891). General Custer himself wrote about the Indian wars in My Life on the Plains (1874) and was the posthumous co-author of The Custer Story (1950).

Custer would probably be called today a "media personality" who understood the value of good public relations and exploited media for his own ends; he frequently invited correspondents to accompany him on his campaigns, and their favorable reportage contributed to his high reputation that lasted well into the 20th century. It is believed that Custer was photographed more than any other Civil War officer, and perhaps more than any other person in the 19th century with the exception of "Buffalo Bill" Cody.

He was fond of flamboyant dress; a witness described his appearance as "like a circus rider gone mad." After being promoted to brigadier general, Custer sported a uniform that included shiny jackboots, tight olive corduroy trousers, a wide-brimmed slouch hat, tight hussar jacket of black velveteen with silver piping on the sleeves, a sailor shirt with silver stars on his collar, and a red cravat. He wore his hair in long glistening ringlets liberally sprinkled with cinnamon-scented hair oil. Later in his campaigns against the Indians, Custer wore a buckskin outfit along with his familiar red tie.

The assessment of Custer's actions during the Indian Wars has undergone substantial reconsideration in modern times. For many critics, Custer was the personification and culmination of the U.S. Government's ill-treatment of the Native American tribes, while others see him as a scapegoat for the Grant Indian policy, which he personally opposed. His testimony on behalf of the abuses sustained by the reservation Indians nearly cost him his command by the Grant administration. Custer once wrote that if he were an Indian, he would rather fight for his freedom alongside the hostile warriors "than be confined to the limits of a reservation".

Many criticized Custer's actions during the battle of the Little Bighorn, claiming his actions were impulsive and foolish, while others praised him as a fallen hero who was betrayed by the incompetence of his subordinate officers. The controversy over who is to blame for the disaster at Little Bighorn rages to this day.