Seeking records from small school in Louisiana

Hello, I am trying to find manuscripts related to a group of small schools (two elementary schools: one for African American students and one for white students, as well as a high school for white students) in a small town (< 1000 residents) in Sabine Parish from 1899-1960. So far, I have checked with the Louisiana Department of Education and the Parish Department of Education, as well as read the published Biennial Reports from the Commissioner of Education and Ancestry's school records. Does anyone have suggestions on where to find this? Any kind of documentation would be great, from financial to curriculum information to attendance records and beyond. Thank you very much for your help.