When Denmark-Norway was drawn into the Napoleonic wars in 1807, the resulting British naval embargo limited the supply of goods, including pharmaceuticals. Maschmann worked with other pharmaceutical wholesaler in the country to avoided medical shortages during these crisis years which extended until the Treaty of Kiel in 1814. In 1839, he turned over management of the pharmacy firm to his eldest son Carl Gustav Maschmann, who died in 1848. He managed the pharmacy until 1856 when his younger son, Bernt Sverdrup Maschmann joined the firm.