19th century

At the turn of the 19th century, Kruszwica was considered to be the smallest Kuyavian town, destroyed by numerous wars, depopulated by diseases and poverty. It was incorporated into the Kingdom of Prussia at the First Partition of Poland on 5th April 1772.
It was the time of a heroic struggle carried on by patriots against the Germanisation of Poles, which was particularly visible at the Spring of Nations 1848. Some insurrectionary committees and units were formed in Kuyavia (in Strzelno, Inowroclaw and Kruszwica). The struggle was also carried out in the field of culture: at the time, a Polish library was opened in Kruszwica and various organizations embracing Polish people were established, for example, The Polish League, The Polish Trade Union, the Society of Industrial Leaders, the Society of Farmers, the Polish Gymnastic Society ‘Goplo Falcon’, the Commerce Youth Society and the Society of Beekeepers.
The upper Notec river regulation completed between 1857 and 1859 resulted in a considerable decrease of Goplo water level, it changed its shoreline and, also, it opened the waterway from Kruszwica to Bydgoszcz Canal.
The oldest preserved urban planning design is from 1837 so it is possible to conclude how the quarters of the town developed. Brick buildings along the main streets and around the Market Square replaced the earlier ones – timber and timber-framing constructions.
At the end of the 19th century, the town extended to the north and the industry developed. In 1881, Kruszwica Sugar Factory was set up. It is one of the oldest sugar companies in Poland. At the time (in 1900), a slaughterhouse was also opened. In 1889, a railway connected Kruszwica to Inowroclaw.

20th century

The 20th century was the time of the development of industry as well as craft and trade. The following companies were established:
-    gasworks (1905)
-        dairy (Dairy Cooperative 1912)
-    Henryk Makowski’s winery, the first winery in Poland (1920)
-    milling plant, later renamed the Polish Grain Company (1925)
-    waterworks with a water tower (1934)
-    edible fats and oils factory (1952-1956)
Due to the town expansion, some changes in the urban planning were introduced. Education, culture and tourism developed. Some schools and a cinema (operating within the sugar factory area in the 1950s) were built, in 1922 Rzepowski Peninsula was adapted for recreation and a library and some sports clubs were established. There was also a plan for erecting a museum.
Kruszwica regained independence on 3rd January 1919 as a result of the Wielkopolska Uprising.
During World War II, Nazi army entered the town. A lot of Kruszwica citizens were murdered in slaughter. The invaders also took action against culture: all associations in Kruszwica were closed down and it was forbidden to speak the Polish language. In those harm conditions, some resistance movement was arranged: in 1942 an organization ‘Piast’ was created. It cooperated with ‘Ojczyzna’ (‘Homeland’), a resistance organization in Poznan.
The Red Army with some Polish Army units freed Kruszwica on 21st January 1945. Since then, the white and red flag has been hanging at the top of the Mouse Tower.