According to Sister Cities International, the program was introduced at a White House conference by President Eisenhower in 1956. A sister city is a long-term partnership between two communities in two countries, intended to foster friendship and understanding between different cultures, to encourage trade and tourism. A sister city is officially recognized after the highest elected or appointed official from both communities sign off on an agreement. A city may have any number of sister cities, with community involvement ranging from a half dozen to hundreds of volunteers. In addition to volunteers, sister city organizations may include representatives from nonprofit organizations, municipal governments, the private sector, and other civic organizations.
Marshfield, Wisconsin has two sister cities, Jáuregui/Luján, Argentina
and Zhangjiagang, China