The U.S. Army does not have any bases in Nigeria as of January 2015. No branch of the military maintains a base or any other type of presence in Nigeria.
The U.S. Army offers active-duty postings in 74 countries besides the United States. African countries where the Army stations active-duty soldiers include Chad, Djibouti, Egypt, Ethiopia, Kenya, Madagascar, Mali, Mauritania, Niger, Senegal, Sierra Leone, Sudan, Tanzania, Tunisia and Uganda.
Most overseas assignments in the Army last a standard tour length of two years. If the assignment is on a base and the soldier's family relocates, this length extends to three years.