Kampen was owner of the growing Kampereiland. From 1500 the islands were leased. The rents were so large that the city did not need to raise taxes.
The Franco-Dutch War, fought by the Republic of the United Netherlands against theKingdom of France, Sweden, the Bishopric of Münster, the Archbishopric of Cologne and the Kingdom of England, marked a definitive end to the enormous power of the city.
Kampen only became well known again in the 19th century. The city was difficult to reach from the sea, because the surrounding wetlands were bogged down and shallow. During the preceding centuries, the watercourse of the river IJssel was dredged several times, but the costs were relatively high and within a few years, the river bogged down again. As the IJssel had several delta-like mouths here, the main route of the river shifted several times. In the 19th century, a new strategy was put in place to counter this problem: some watercourses were dammed to allow for more water at a higher speed through one or two main routes. This had the advantage that less sand and silt were deposited and resulted in a river course that "swept itself clean". A key figure in this story is city architect Nicolaas Plomp, who, besides his work for the current IJssel front of the city of Kampen, was also involved in hydraulic engineering. Due to the emerging industry in the 19th century and the importance of roads and railways for the economy, highways and paved roads were constructed to replace transportation over sand and mud roads
