Once the fire had ended, the smoldering remains were still too hot for a survey of the damage to be completed for many days. Eventually, the city determined that the fire destroyed an area about long and averaging wide, encompassing an area of more than . On October 11, 1871,
U.S. Army Lieutenant General
Philip H. Sheridan came to the aid of the city. Chicago mayor
Roswell B. Mason issued a proclamation that declared
martial law and placed the city under Sheridan's temporary control: "The Preservation of the Good Order and Peace of the city is hereby intrusted to Lieut. General P.H. Sheridan, U.S. Army." Sheridan's command structure consisted of a mix of regular troops, militia units, police, and a specially organized civilian group "First Regiment of Chicago Volunteers". Former Lieutenant-Governor William Bross, and part owner of the
Tribune, later recollected his response to the arrival of Gen. Sheridan and his soldiers: "Never did deeper emotions of joy overcome me. Thank God, those most dear to me and the city as well are safe." For two weeks, Sheridan's men patrolled the streets, guarded the relief warehouses, and enforced other regulations. On October 24 the troops were relieved of their duties and the volunteers were mustered out of service. Of the approximately
324,000 inhabitants of Chicago in 1871, 90,000 Chicago residents (about 28% of the population) were left homeless. 120 bodies were recovered, but the death toll may have been as high as 300. The county
coroner speculated that an accurate count was impossible, as some victims may have drowned or had been incinerated, leaving no remains. In the days and weeks following the fire, monetary donations flowed into Chicago from around the country and abroad, along with donations of food, clothing, and other goods. These donations came from individuals, corporations, and cities. New York City gave $450,000 (equivalent to $ today) along with clothing and provisions,
St. Louis gave $300,000 (equivalent to $ today), and the
Common Council of London gave 1,000 guineas, as well as £7,000 from private donations. In
Greenock, Scotland (pop. 40,000) a town meeting raised £518 on the spot.
Cincinnati,
Cleveland, and
Buffalo, all commercial rivals, donated hundreds and thousands of dollars.
Milwaukee, along with other nearby cities, helped by sending fire-fighting equipment. Food, clothing and books were brought by train from all over the continent. Mayor Mason placed the
Chicago Relief and Aid Society in charge of the city's relief efforts. Public buildings were opened as places of refuge, and saloons closed at 9 in the evening for the week following the fire. Many people who were left homeless after the incident were never able to get their normal lives back since all their personal papers and belongings burned in the conflagration. After the fire, A. H. Burgess of London proposed an "English Book Donation", to spur a free library in Chicago, in their sympathy with Chicago over the damages suffered. The fire also led to questions about development in the United States. Due to Chicago's rapid expansion at that time, the fire led to Americans reflecting on industrialization. Based on a religious point of view, some said that Americans should return to a more old-fashioned way of life, and that the fire was caused by people ignoring traditional morality. On the other hand, others believed that a lesson to be learned from the fire was that cities needed to improve their building techniques.
Frederick Law Olmsted observed that poor building practices in Chicago were a problem: Almost immediately, the city began to rewrite its fire standards, spurred by the efforts of leading insurance executives, and fire-prevention reformers such as
Arthur C. Ducat. Chicago soon developed one of the country's leading fire-fighting forces. Business owners and land speculators such as
Gurdon Saltonstall Hubbard quickly set about rebuilding the city. The first load of lumber for rebuilding was delivered the day the last burning building was extinguished. By the
World's Columbian Exposition 22 years later, Chicago hosted more than 21 million visitors. The
Palmer House hotel burned to the ground in the fire 13 days after its grand opening. Its developer,
Potter Palmer, secured a loan and rebuilt the hotel to higher standards, across the street from the original, proclaiming it to be "The World's First Fireproof Building". In 1956, the remaining structures on the original O'Leary property at 558 W.
DeKoven Street were torn down for construction of the Chicago Fire Academy, a training facility for Chicago firefighters, known as the Quinn Fire Academy or Chicago Fire Department Training Facility. A bronze
sculpture of stylized flames, entitled
Pillar of Fire by
Egon Weiner, was erected on the point of origin in 1961. ==Surviving structures==