From the Overview: "Congress authorizes, appropriates, and oversees U.S. assistance to sub-Saharan Africa ('Africa'), which received over a quarter of U.S. aid obligated in FY2018. Annual State Department- and U.S. Agency for International Development (USAID)-administered assistance to Africa increased more than five-fold over the past two decades, primarily due to sizable increases in global health spending and more incremental growth in economic and security assistance. State Department and USAID-administered assistance allocated to African countries from FY2019 appropriations totaled roughly $7.1 billion. This does not include considerable U.S. assistance provided to Africa via global accounts, such as emergency humanitarian aid and certain kinds of development, security, and health aid. The United States channels additional funds to Africa through multilateral bodies, such as the United Nations and World Bank."
CRS Report for Congress, R46368
Congressional Research Service: https://crsreports.congress.gov/