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.[1]
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.[2] 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.[1] 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.[3] 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.[1] 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.[1][4]
After 1986, La Union elected its representatives from its two single-member congressional districts restored under a new constitution.[5]