The document discusses changes and exchanges in Africa between 1750-1870, including the establishment of new states in Africa, Muslim reform movements in West Africa that led to new states like the Sokoto Caliphate, modernization efforts in Egypt under Muhammad Ali, European exploration of Africa's rivers, abolition of the slave trade, growth of legitimate trade, expansion of palm oil exports, development of secondary empires based on the ivory and slave trades, and British rule over India through the East India Company.