1877 Saint Barthélemy status referendum
A referendum on re-integration into France was held in the Swedish colony of Saint Barthélemy in October 1877. The island had been a colonial possession of Sweden since Sweden acquired it from France in 1784, but the unprofitability of the island led to Sweden to attempt to sell it.
Source: Wikipedia — 1877 Saint Barthélemy status referendum (CC BY-SA 4.0)