 The component cities of Biñan, Calamba, and Santa Rosa, while remaining integral parts of the province, granted their separate congressional representations in 2015, 2018, and 2019, respectively.Laguna was initially divided into two representative districts in 1907.When seats for the upper house of the Philippine Legislature were elected from territory-based districts between 1916 and 1935, the province formed part of the fourth senatorial district which elected two out of the 24-member senate.