Sziszek - the biggest Croatian river port
The beginning of the 19th century caught a divided Sisak, the one on the left bank of the Kupa River which belonged to Kaptol, and the one on the right bank under direct government of the Military Frontier. In 1838 Sisak got the status of the free market town with the town hall and coat of arms, and during the Illyrian movement, Sisak Illirians on 2 October 1839 performed the play ′Juran and Sofija′ by Ivan Kukuljević , thereby marking the beginning of stokavian drama in Newer Croatian literature.
The role of Sisak in the industrial life of Croatia became more important by opening the waterway along the Sava and the Kupa in 1842, and especially by constructing the railway line in 1862. After the abatement of the Military Frontier, civil and military Sisak united in one town municipality, so in 1874 Sisak became a free royal town.
Sisak – Town of Croatian Victories
The twentieth century brought industrialization of Sisak which would particularly intensify after World War I, when the population increased and the demographic structure changed. Before the World War II, Sisak was an important centre of river traffic, and metallurgic, chemical, wood and food industry. A great number of industrial workers favoured strong development of workers′ and union movement. A logical sequence of that all was the organization of the Sisak Partisan Detachment. After World War II Sisak became one of industrially most developed towns of Croatia.