[1] Prior to its creation as an independent province, Agusan was divided between the provinces/districts of Misamis, and Surigao during the Spanish colonial period.

On August 20, 1907, Agusan was separated from Misamis and Surigao, composed of the sub-provinces of Bukidnon and Butuan, by virtue of Act No.

[4] During World War II and the Japanese occupation of the Philippines in 1942, Japanese forces landed in Agusan and occupied the area until they were defeated by combined American and Philippine Commonwealth troops, along with recognized guerrilla units, in 1945.

The law was ratified through a plebiscite held on November 14, 1967, dissolving the old province.

[7] Agusan was initially under the Bureau of Non-Christian Tribes and unrepresented in the Philippine Assembly that existed until 1916.