The district was created under the 1916 Jones Law from the western Visayas provinces of Antique, Negros Occidental, Negros Oriental and Palawan.
[1] The district was represented by a total of seven senators throughout its existence.
It was abolished in 1935 when a unicameral National Assembly was installed under a new constitution following the passage of the Tydings–McDuffie Act which established the Commonwealth of the Philippines.
Since the 1941 elections when the Senate was restored after a constitutional plebiscite, all twenty-four members of the upper house have been elected countrywide at-large.
It was last represented by Gil Montilla and Isaac Lacson of the Nacionalista Democrático.