Question: Who remarked that Lincoln looked cheerful the morning of his assassination?
About the article "Assassination of Abraham Lincoln", section "Day of the assassination".

Candidate passages:
Lincoln's day started well for the first time in a while.
Hugh McCulloch, the new Secretary of the Treasury, remarked that on that morning, "I never saw Mr. Lincoln so cheerful and happy".
No one could miss the difference.
For months, the President had looked pale and haggard.
Lincoln himself told people how happy he was.
This caused First Lady Mary Todd Lincoln some concern, as she believed that saying such things out loud was bad luck.
Lincoln paid her no heed.
At around noon, while visiting Ford's Theatre to pick up his mail (Booth had a permanent mailbox there), Booth learned from the brother of John Ford, the owner, that the President and General Grant would be attending the theatre to see "Our American Cousin" that night.
Booth determined that this was the perfect opportunity for him to do something "decisive".
He knew the theater's layout, having performed there several times, as recently as the previous month.
That same afternoon, Booth went to Mary Surratt's boarding house in Washington, D.C. and asked her to deliver a package to her tavern in Surrattsville, Maryland.
He also requested Surratt to tell her tenant who resided there to have the guns and ammunition that Booth had previously stored at the tavern ready to be picked up later that evening.
She complied with Booth's requests and made the trip, along with Louis J. Weichmann, her boarder and son's friend.
This exchange, and her compliance in it, would lead directly to Surratt's execution three months later.
At seven o'clock that evening, John Wilkes Booth met for a final time with all his fellow conspirators.
Booth assigned Lewis Powell to kill Secretary of State William H. Seward at his home, George Atzerodt to kill Vice President Andrew Johnson at his residence, the Kirkwood Hotel, and David E. Herold to guide Powell to the Seward house and then out of Washington to rendezvous with Booth in Maryland.
Booth planned to shoot Lincoln with his single-shot Derringer and then stab Grant with a knife at Ford's Theatre.
They were all to strike simultaneously shortly after ten o'clock that night.
Atzerodt wanted nothing to do with it, saying he had only signed up for a kidnapping, not a killing.
Booth told him he was in too far to back out. 
On March 9, 1865, McCulloch was appointed as the 27th Secretary of the Treasury by President Abraham Lincoln.
His appointment was largely due to his influence with existing state banks.
McCulloch later remarked that on the morning of Lincoln's assassination, "I never saw Mr. Lincoln so cheerful and happy...
The burden which had been weighing upon him for four long years, and which he had borne with heroic fortitude, had been lifted; the war had been practically ended; the Union was safe."
He continued to serve in the Presidential Cabinet of Andrew Johnson until the close of his administration in 1869.
Immediately confronted with inflation caused by the government's wartime issue of greenbacks, he recommended their retirement and a return to the gold standard.
In McCulloch's first annual report, issued on December 4, 1865, he strongly urged the retirement of the legal tenders or greenbacks as a preliminary to the resumption of specie payments.
However this would have reduced the supply of currency and was unpopular during the period of postwar reconstruction and westward expansion.
In accordance with this suggestion an act was passed, on March 12, 1866, authorizing the retirement of not more than $10,000,000 in six months and not more than $4,000,000 per month thereafter.
This act met with strong opposition and was repealed on the February 4, 1868, after only $48,000,000 had been retired.
The battle over its revival raged for the next fifty years.
McCulloch was also disappointed by the decision of the United States Supreme Court upholding the constitutionality of the legal tenders.
During his tenure, McCulloch maintained a policy of reducing the federal war debt and the careful reintroduction of federal taxation in the South.
Soon after the close of his term of office McCulloch went to England, and spent six years (1870–1876) as a member of the banking firm of Jay Cooke, McCulloch & Co. From October 1884 until the close of President Chester A. Arthur's term of office in March 1885 he served as the 36th Secretary of the Treasury.
During his six months in office at that time, he continued his fight for currency backed by gold, warning that the coinage of silver, used by then as backing for currency, should be halted. 
Despite his excellent service in the Army quartermaster department, Ekin is remembered largely for his participation as a member of the military tribunal that heard the case against eight conspirators in the assassination of President Lincoln. 
Presidents assassinated.
Abraham Lincoln.
The assassination of Abraham Lincoln took place on Good Friday, April 14, 1865, at approximately 10:15 p.m. Lincoln was shot once in the back of his head with a .44 caliber Derringer pistol by actor and Confederate sympathizer John Wilkes Booth while attending a performance of "Our American Cousin" at Ford's Theatre in Washington, D.C. with his wife, Mary Todd Lincoln, and two guests.
Major Henry Rathbone tried to stop Booth from escaping, but Booth stabbed him in the chest and slashed his arm to the bone with a dagger that he was also carrying.
Soon after being shot, Lincoln's wound was declared to be mortal.
Lincoln died the following morning at 7:22 a.m. on April 15 without regaining consciousness.
Booth was tracked down by Union soldiers and was shot and killed by Sergeant Boston Corbett on April 26, 1865.
Booth apparently believed that killing Lincoln would radically change U.S. policy toward the South. 
The Abraham Lincoln Library and Museum in Harrogate, Tennessee and located on campus of Lincoln Memorial University, exhibits items such as the cane that Lincoln used at Ford's Theatre the night of his assassination, a collection of about 30,000 books, and art exhibits.