Question: How did William McKinley die?
About the article "Assassination of William McKinley", section "Abstract".

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 William McKinley, 25th President of the United States  McKinley (surname)  
  William Henry Harrison (1841, pneumonia and pleurisy from undisclosed illness)  Zachary Taylor (1850, gastroenteritis)  Abraham Lincoln (1865, assassinated)  James Garfield (1881, assassinated)  William McKinley (1901, assassinated)  Warren G. Harding (1923, suspected heart attack)  Franklin Delano Roosevelt (1945, cerebral hemorrhage)  John F. Kennedy (1963, assassinated) Facts.
Died in office.
Note: Of the presidents listed above, Zachary Taylor, Abraham Lincoln and William McKinley are the only ones to have a former president die during their administrations and prior to their subsequent deaths; James Polk died on Zachary Taylor's 103rd day in office, John Tyler and Martin Van Buren died during Abraham Lincoln's administration and Benjamin Harrison died 187 days before the assassination of William McKinley.
William Henry Harrison, James Garfield and Warren G. Harding did not have a former president, vice president or First Lady die during their administrations.
All these Presidents were survived by at least one predecessor, though William McKinley and Franklin Roosevelt are the only ones with only one living predecessor at the time of their deaths (Grover Cleveland and Herbert Hoover respectively).
Of the four presidents to die by assassination, John F. Kennedy is the only one to die on the same day he was attacked. 
  President William McKinley High School  
Within minutes of the shots, the news was conveyed around the world by telegraph wire, in time for the late newspaper editions in the US.
In the era before radio, thousands stood in cities across the country outside newspaper offices, awaiting the latest bulletin from Buffalo.
Fears that McKinley would not survive the day of his shooting were allayed by reassuring bulletins issued by Cortelyou based on information from the doctors.
Large, threatening crowds assembled outside Buffalo police headquarters where Czolgosz was brought.
Word that he had admitted to being an anarchist led to attacks on others of that belief: one was nearly lynched in Pittsburgh.
At the Milburn House, McKinley seemed to be recovering.
On Saturday, September 7, McKinley was relaxed and conversational.
His wife was allowed to see him, as was Cortelyou; the President asked his secretary, "How did they like my speech?"
and was pleased on hearing of positive reactions.
Meanwhile, Vice President Roosevelt (who had been on a Vermont vacation), much of the Cabinet, and Senator Hanna hurried to Buffalo.
Cortelyou continued to issue encouraging bulletins.
The President was permitted few visitors, and complained of loneliness.
As the crisis seemed to have passed, dignitaries started to leave on September 9, confident of the President's recovery.
Roosevelt left for a vacation in the Adirondack Mountains after expressing outrage that Czolgosz might serve only a few years under New York State law for attempted murder, the maximum penalty for attempted murder in New York at that time being ten years.
Attorney General Philander Knox went to Washington, searching for a means to bring Czolgosz under federal law.
Secretary of State John Hay had been closely associated with the two presidents to be assassinated: he had been Lincoln's secretary, and a close friend of James Garfield.
He arrived on September 10; met at the station by Babcock with an account of the President's recovery, Hay responded that the President would die.
McKinley biographer H. Wayne Morgan wrote of the week following the shooting:His hearty constitution, everyone said, would see him through.
The doctors seemed hopeful, even confident ...
It is difficult to understand the cheer with which they viewed their patient.
He was nearly sixty years old, overweight, and the wound itself had not been thoroughly cleaned or traced.
Precautions against infections, admittedly difficult in 1901, were negligently handled.
According to McKinley biographer Margaret Leech, McKinley's apparent recovery "was merely the resistance of his strong body to the gangrene that was creeping along the bullet's track through the stomach, the pancreas, and one kidney".
Another X-ray machine was sent from New Jersey by its inventor, Thomas Edison.
It was not used on the President; sources vary on why this was—Leech stated that the machine, which she says was procured by Cortelyou and accompanied by a trained operator, was not used on orders of the doctors in charge of McKinley's case.
Miller recounts that doctors attempted to test it on a man of about McKinley's size, but it proved to be missing a crucial part, much to Edison's embarrassment.
McKinley had been given nutritive enemas; on September 11, he took some broth by mouth.
When it seemed to do him good, the following morning they allowed him toast, coffee, and chicken broth.
His subsequent pain was diagnosed as indigestion; he was given purgatives and most doctors left after their evening consultation.
In the early morning of September 13, McKinley suffered a collapse.
Urgent word to return to Buffalo was sent to Vice President Roosevelt, from the nearest telegraph or telephone in the Adirondack wilderness; a park ranger was sent to find him.
Specialists were summoned; although at first some doctors hoped that McKinley might survive with a weakened heart, by afternoon they knew the case was hopeless.
As yet unknown to the doctors, gangrene was growing on the walls of his stomach and toxins were passing into his blood.
McKinley drifted in and out of consciousness all day; when awake he was the model patient.
By evening, McKinley too knew he was dying, "It is useless, gentlemen.
I think we ought to have prayer."
His friends and family were admitted, and the First Lady sobbed over him, "I want to go, too.
I want to go, too."
Her husband replied, "We are all going, we are all going.
God's will be done, not ours" and with final strength put an arm around her.
He may also have sung part of his favorite hymn, "Nearer, My God, to Thee", although other accounts have her singing it softly to him.
Ida McKinley was led away, her place briefly taken by Senator Hanna.
Morgan recounts their final encounter, "Sometime that terrible evening, Mark Hanna had approached the bedside, tears standing in his eyes, his hands and head shaking in disbelief that thirty years of friendship could end thus."
When a tentative, formal greeting gained no coherent response, Hanna "cried out over the years of friendship, 'William, William, don't you know me?
' "At 2:15 a.m. on Saturday, September 14, 1901, President McKinley died.
At the time of McKinley's death, Roosevelt was on his return journey to Buffalo, racing over the mountain roads by carriage to the nearest railroad station, where a special train was waiting.
When he reached that station at dawn, he learned of McKinley's death. 
 Philippines  Fort William McKinley (now Fort Bonifacio) in Metro Manila  McKinley Road, a major thoroughfare in Metro Manila United States  Mount McKinley McKinley, West Virginia  McKinley County, New Mexico  McKinley Township, Emmet County, Michigan  McKinley Township, Huron County, Michigan  McKinley, Minnesota (disambiguation) (multiple)  McKinley, Wisconsin (disambiguation) (multiple)