some online info Roberts International Airport, Monrovia ( pretty clear why it sets a standard, I wonder how JKIA which I think is more modern and commercial is supposed to compete with this though )  : http://en.wikipedia.org/wiki/Roberts_International_Airport

 

The facility with its 11,000 feet (3,400 m) long runway is an emergency landing site for the United States' Space Shuttle program and the principal international airport in the country.

 

Some history :

In 1942, Liberia signed a Defense Pact with the United States. This commenced a period of strategic road building and other construction related to US military interests in checking the expansion of the Axis, particularly in terms of the Italian occupation of North Africa. The Airport was originally built by the United States government as an Air Force base as part of these activities.Robertsfield Airport was built with runways long enough for B-47 Stratojet bombers to land for refueling, giving Liberia what was for many years the longest runway in Africa.^[3] President Franklin D. Roosevelt of the United States had lunch with President Edwin J. Barclay of Liberia at Roberts International Airport, during FDR's visit to Liberia in January 1943.