
The East African Federation is a proposed political union of Burundi, Kenya, Rwanda, South Sudan, Tanzania, and Uganda. The proposed capital is Arusha.
The leaders of six African countries have big plans for East Africa. They want a unified currency, a modern infrastructure, and long-lasting peace in a part of the world that's seen its share of unrest.
The East African Federation is what they have in mind. It's an idea that's been brewing since the early 1960s, which is when four of the six countries (Kenya, Tanganyika, Uganda, and Zanzibar) gained independence from the UK.
The proposed political union of Burundi, Kenya, Rwanda, South Sudan, Tanzania, and Uganda would form a new federated sovereign state, and it could happen soon. In September 2018, steps were taken to begin creating a regional constitution.
If this group of African nations can complete the union, the resulting county, the East African Federation, would cover just short of a million square miles, making it Africa's largest country, and the 10th-largest country in the world.
Combining seven populations into one would add up to nearly 179,000,000 people. At that point, Nigeria would be the only African nation with a greater population. In fact, the East African Federation would have the 8th-largest population in the world, beating Russia, Japan and Mexico.
One proposed change that's going to happen even if the union doesn't pan out is the standardization of the region's currency.
An economic bloc called the East African Community (EAC) is moving into the advanced stages of a monetary union. The bloc’s Heads of States signed the East African Monetary Institute Bill in February 2019. That's a major step in unifying the regions currency, and the high-level support this effort has means the transition is practically inevitable.
The proposed currency is the East African shilling, and projections indicate that it will be the common currency of five of the six member nations by 2023.
If you want to get a head start on memorizing African capitals, you may be interested in the fact that the capital of the East African Federation, if it ever exists, will be the city of Arusha, in what is now Tanzania.
Read more on Wikipedia: East African Federation

Arusha, the proposed capital of the East African Federation.