What was the most significant factor that prevented many African states from achieving political stability in the decades after their independence?

Africa will remain turbulent because it is poor and young, but also because it is growing and dynamic. Development is disruptive but also presents huge opportunities. The continent needs to plan accordingly.

Levels of armed conflict in Africa rise and fall. Data from the Uppsala Conflict Data Program, the Global Terrorism Database and others indicate that armed conflict peaked in 1990/91 at the end of the Cold War, declined to 2005/6, remained relative stable to 2010/11 and then increased to 2015, although it peaked at lower levels than in 1990/91 before its most recent decline.

Armed conflict has changed. Today there are many more non-state actors involved in armed conflict in Africa – representing a greater fracturing of armed groupings. So it’s not a matter of “government vs an armed group” but a “government vs many armed groups”. Insurgents are often divided and sometimes even fighting amongst themselves. This greater fragmentation complicates peacemaking.

i would go with the last one

abraham lincoln  (february 12, 1809  – april 15, 1865) was an american statesman, politician, and lawyer who served as the 16th  president of the united states  from 1861 until  his assassination  in april 1865. lincoln led the nation through the  american civil war, its bloodiest war and its greatest moral, constitutional, and political crisis.[2][3]  he preserved the  union,  abolished slavery, strengthened the  federal government, and modernized  the u.s. economy.