In the beginning of the 19th century Malmö was a sleepy, small town with less than 5 000 inhabitants. The town was surrounded by strong fortifications and a moat. In the government´s opinion there was no need for a strong fortress in the south of Sweden anymore and the cost of maintenance was too high. Malmö was allowed to demolish the fortifications at its own expense. This opened up for the expansion of the town. A new town plan was produced with two new squares, promenades and a new canal around the former Old Town. As a part of the agreement between the government and Malmö the Rörsjö-marshes were drained allowing the town to expand beyond its former limits. The population rose rapidly especially during the latter part of the century. In 1850 there were around 13 000 inhabitants in the Malmö. Thirty years later more than 38 000 and in 1900 there were 60 587 people living in Malmö. There were two more factors which contributed two this growth: the building and expansion of the harbour and the building of the railways in the 1860s. Söderport, Österport, Norra Vallgatan and Bastion Älvsborg remind us today of times gone by.The essay is based on documents and maps in archives and on presentations by scholars of the 20th century.