Republic Act No. 4979, approved in a plebiscite held simultaneously with the 1967 elections, split the old Agusan Province into Agusan del Norte and Agusan del Sur and provided them each with a congressional representative.
Republic Act No. 4979, passed through a public vote alongside the 1967 elections, split the previous Agusan Province into two separate provinces: Agusan del Norte and Agusan del Sur, with each receiving a single congressional representative.