the province of agusan del sur was established on june 17, 1967, under "republic act no. 4969" providing for the division of the province of agusan into agusan del norte and agusan del sur. in january 1970, the first set of provincial officials assumed office after the provincial election of november, 1969. the same law provided that the capital of agusan del sur be the municipality of prosperidad. the government center has been set up in barangay patin-ay.