[1] The non-Christian areas were to be collectively represented in the upper house's 12th senatorial district by two senators, both appointed by the Governor-General.
The voters of Agusan Province were finally given the right to elect their own representative through popular vote beginning in 1935 by virtue of Article VI, Section 1 of the 1935 Constitution.
[2] During the Second World War, the Province of Agusan sent two delegates to the National Assembly of the Japanese-sponsored Second Philippine Republic: one was the provincial governor (an ex officio member), while the other was elected through a provincial assembly of KALIBAPI members during the Japanese occupation of the Philippines.
Upon the restoration of the Philippine Commonwealth in 1945 the province retained its pre-war lone congressional district.
When Butuan became a chartered city in 1950, it remained part of the representation of Agusan, per Section 89 of Republic Act No.