Who was the songhai leader who instituted a series of reforms through his empire, including opening up government office to people from any background: ?

The Songhai leader who left a legacy through the reforms in his empire was Muhammad I Askia or Muhammad Ture. Under his governance, he began organizing his land by setting up regions which were under the leadership of governors together with their armies under the ruling of a general and an admiral.  He also began setting departments and offices for finance, justice, interior, agriculture, etc. He indeed strengthened the administrative system of what his predecessor had left unorganized.  After a lot of quests and changes in his governance, he was able to expand and strengthened his empire. In 1528, he was defeated and overthrown by his son, Askia Musa. 

racism and segregation.

he sent troops to protect the students as they entered the school.