In his classic two-volume work, The War With Mexico (Macmillan Co., NY.  1911), Justin Smith, perhaps the pre-eminent historian on the Mexican War, wrote:

"When the first thin streak of dawn glimmered forth behind the gray volcanoes, and our cannon at Belén garita were on the point of opening fire, a white flag and an invitation to enter the capital reached Quitman.  First making sure there was no deception, he advanced; and after stopping about half an hour at the citadel he moved forward under a splendid sun to the grand plaza, which fronted the palace and the cathedral, with [Persifor] Smith's Brigade, the Marines, the New York volunteers and Steptoe's battery.

As a triumphal procession the command looked rather strange.  Quitman and Smith marched at its head on foot -- the former with only one shoe; and behind them came troops decorated with mud, the red stains of battle and rough bandages, carrying arms at quite haphazard angles.

No less astonishing looked the city, for sidewalks, windows, balconies and housetops were crowded with people.  Except for the silence, the countless white handkerchiefs and the foreign flags, it might have been thought a holiday.  Before the palace, which filled the east side of the plaza, the troops formed in line of battle. Officers took their places at the front, and when Captain Roberts hoisted a battle-scarred American flag on the staff of the palace at seven o'clock, arms were presented and the officers saluted.

Soon, loud cheering was heard.  A few squares away the commander-in-chief, escorted by cavalry with drawn swords, had reached Worth's command, which had stopped at six o'clock by orders opposite the high ash trees of the Alameda.  A clatter of galloping hoofs followed; and in another moment, amidst the involuntary applause of the Mexicans, General Scott, dressed in full uniform and mounted on a tall, heavy bay charger, dashed with his staff and Harney's dragoons into the grand plaza -- his noble figure, gold epaulets and snowy plumes, resplendent under the brilliant sun, fitly typifying the invisible glory of his unkempt and limbering army. . .

In stentorian tones the commander-in-chief appointed Quitman Governor of the city . . ."

In the coming weeks, when the Aztec Club was formed in the City of Mexico, Gen. John A. Quitman became its first president.