The earliest written records of West African history were written in Arabic because

The earliest written records of West African history were written in Arabic because several Arabic schools existed in West Africa shortly after the advent of Islam. As Islam spread to West Africa, Arabic became the language of learning and scholarship. Arab traders and scholars also brought Arabic script to the region, and many West Africans embraced Islam and learned to read and write in Arabic. This led to the creation of many Arabic manuscripts documenting West African history, literature, and religion.