The Netherlands gained Suriname through the Treaty of Breda (1667), which ended the Second Anglo-Dutch War. The terms were a straight territorial swap:
At the time, Suriname was seen as the more valuable prize due to its booming sugar plantations (worked by enslaved Africans). New Netherland was considered a marginal fur-trading outpost. History proved otherwise, but the deal stood. Suriname remained Dutch until independence in 1975.