La Union's at-large congressional district
La Union's at-large congressional district is an obsolete electoral district that was used for electing members of Philippine national legislatures in La Union before 1987. La Union first elected its representatives at-large during the 1898 Philippine legislative election for a seat in the Malolos Congress, the National Assembly of the First Philippine Republic, with additional seats granted to two appointed delegates. Following the installation of U.S. civil government in 1901 and the reorganization of provinces for the Philippine Assembly, La Union was divided into a first and second district. The  provincewide electoral district was re-created ahead of the 1943 Philippine legislative election for a seat in the National Assembly of the Second Philippine Republic, with an additional seat assigned to its provincial governor. The district became inactive again following the restoration of the House of Representatives in 1945 when La Union returned to electing its representatives from its two districts. In the unicameral Batasang Pambansa that replaced the House in 1978, La Union was included in the multi-member regional electoral district of Region I (Ilocos Region) for its interim parliament. The district was again utilized in the 1984  Philippine parliamentary election when La Union was granted two seats in the regular parliament. After 1986, La Union elected its representatives from its two single-member congressional districts restored under a new constitution.