While I can't comment on the Americas as a whole, in Suriname, they represented roughly a third of the white population in the 17th and 18th centuries. These were Jews that had originally fled from Spanish and Portuguese exile into Dutch domains, which were more welcoming of Jews. Once in Suriname, they did indeed have an impact on the local economy, running plantations, and importing large numbers of slaves. The city of Jodensavanne, for instance, became an important port in Suriname, and an agricultural hub, and Jews continued to have special status in Suriname until 1825.