I remember in HS before common core the only mention we ever had of African history was Ghana, Mali, and Songhai, and Mansa Musa. It’s great you want to expose your students to more. I’m an archaeologist who works primarily in Africa now. I’m on my phone on my lunch break so forgive me any typos or shortcomings. I’ll return to edit later.

By “put in context” do you mean more about western Sahelian history or more urban trading states in Africa? If the latter, there were many. Here are a few in chrono order:

Meroe in modern Sudan. Culmination of a series of evolving states which had once ruled over Egypt. Adapted Egyptian royal customs and religion to their own distinct culture. Built more pyramids than Egypt and had many powerful female rulers. Primary source of wealth was their tremendous production of iron. Hills of slag still dot the area and deforestation for charcoal may have contributed to its decline.

Aksum in modern Ethiopia. A major state on the global stage. Aksumite coins were minted to the same standard as the Byzantine state and Greek was used in some public monuments to facilitate international trade. Royal tomb goods included Roman wine amphora and Aksumite coins have been found as far away as India. The state was even mentioned in the Periplus of the Erythrean Sea, a 1st century Greek merchant’s guide. It was succeeded by a number of pretty fabulous places like Lalibela with its rock hewn churches and Gondar with its castles combing Jesuit and Indian influence. All three are UNESCO World Heritage sites. Cities aside, Ethiopia also has a great history as a Christian nation since the 300s, a state with a continuous monarch that stretched from Aksum to 1974, and the only state in Africa never successfully colonized.

Great Zimbabwe in modern Zimbabwe, as well as its preceding and successor cities. GZ is romantically enigmatic due, sadly, to its horrible ransacking by European looters. We know historically though that it was the capital of a vast state that grew wealthy on cattle ranching and the royally-organized mining of gold. Much of the gold was traded to my next entry, the Swahili Coast cities, where it then went into international circulation.

Swahili cities extend across the Indian Ocean coastline from southern Somalia to northern Mozambique. They have their origins in indigenous communities in the 7th or 8th centuries, but become major cosmopolitan trade cities with their own uniquely international culture, language, and architecture by the 12th century and many continued to thrive even through both Portuguese and Omani colonialism. Kilwa Kisiwani is one of the most famous cities and has an amazing palace with a pool/bath overlooking the sea that to this day I am still jealous of. Lol. The Swahili were major maritime merchants and sailors in the Indian ocean. Their cities are distinctive for their use of coral in construction and sculpture.

There are many more in central and west Africa too. You might look up Benin City and Dahomey for example which flourished largely on European trade.

Graham Connah’s African Civilizations is a great resource you might check out. The third edition gets a little lost in the weeds of detail imho but has more expansive coverage. Kevin Shillington’s History of Africa is a reasonably good college textbook covering this stuff too (stick to the most recent eds though as his earlier eds lagged far behind contemporary scholarship).

Mark Horton’s Swahili Corridor article is a little dated but very accessible.

I have a few others but have to run. Jenne Jeno comes to mind. Heterarchical social org.