History and Old Stuff...
The authors of my 1941 Social Studies book, Our World Today, ask the readers to imagine an airplane ride over the continent of Africa...
Continuing along our airplane route southward from Air [a mountainous area of the Sahara], we soon notice a change in the appearance of the country. The yellowish gray of the desert is giving way to a light green color. Descending near the earth, we see that we are passing over grasslands, with scattered shrubs and trees. This is the Sudan.They didn't know about the oil of the southern Sudan in 1941. Or maybe it didn't seem worth mentioning.
The Sudan is a broad belt of grasslands lying between the Sahara and the tangled growth of the jungle bordering the equatorial forests of central Africa. It is within the Tropical Zone. The western part belongs to the French and is included in French West Africa. The eastern part belongs to the English and is known as Anglo-Egyptian Sudan.
It is a region of summer rains. The annual rainfall varies from about ten inches near the Sahara to twenty or more along the southern border. The Sudan is one of the most promising agricultural districts of Africa. The grasslands are good for grazing cattle and some parts will grow cotton and other crops usually grown in the warm temperate zones.
Source: Our World Today (p. 110-111), a geography textbook written by De Forest Stull and Roy W. Hatch and copyrighted in 1941 by Allyn and Bacon, Boston, MA