First War of Independence 1857 In the 19th century Kanpur was an important British garrison with barracks for 7,000 soldiers. In 1857, during the First War of Independence (also known as the Indian mutiny), 900 British were besieged in the fortifications for 22 days by rebels under Nana Sahib. They surrendered on the agreement that they would be given safe passage to the nearby Suttee Ghat whereupon they would board barges and be allowed to go by river to Allahabad . However as they boarded the boats they were fired upon by cannon. Many were killed and the remaining 200 were brought back to shore where they were locked-up in insufferable conditions in a building called the Bibigarh. After some time, when it was apparent that the British under General Havelock were likely to retake Kanpur , the captors decided to execute their hostages. The prisoners, about two-thirds of whom were women, children & babies, were butchered by their captors three days before the British entered the city on July 18. The corpses were thrown into a deep well nearby.

The Bibighar was dismantled by the British during the reoccupation of Kanpur , and a memorial railing and a cross were raised at the site of the well. The well is now bricked over. Only the remains of a circular ridge survive, which can still be seen at the Nana Rao Park . The Kanpur Memorial Church – `All Souls' Cathedral' - was raised in honor of the fallen at the north-east corner of Wheeler's entrenchment in 1862 by the British. The marble gothic screen with the famous `mournful seraph' was transferred to the churchyard of All Souls' Church after independence in 1947, and in its place a bust of Tantiya Tope installed as Nana Rao Park.

Development of Industries After 1857 it became an important center of the leather and textile industries. Government Harness and Saddler Factory was started for supplying leather material for army in 1860, followed by Cooper Allen & Co. in 1880. The first cotton textile mill, the Elgin Mills were started in 1862 and Moiré Mills in 1882. The British India Corporation (BIC) was headquartered here and led the development of many industries. The Juggilal Kamlapat Singhania family launched many industrial units between 1930 and 1970. The group is known as J K Group of Industries till date. The Jaipuria family contributed to the patriotic cause, by building the Swadeshi Cotton Mills in response to charges that the foreign rulers were raiding India of its cotton only to sell back textiles to the residents. Kanpur was known as the "Manchester of India" during the 20th Century. As of now, the city owns many leather tanneries, a 2-wheeler factory owned by LML India, under collaboration with Italy 's Piaggio; and over a dozen Defence Ordnance Factories such as Small-Arms Factory, Ordnance Parachute Factory etc. It is also home to the pan masala and gutkha industry.

Many of the British contributed vigorously to charitable causes in the city by building the Ursula Horseman Hospital , the "Hallet" Hospital, Harcourt Butler Technological Institute, by protecting the Allen Forest (now a Zoo) and many other efforts. Most of these are now renamed, though a lot of residents still call them by their old names. However the distortion of names is most visible at the railway crossing bridge next to the Railway Station, where the now-closed Murray Company is conveniently called Mari (Dead) Company.