Political map of Sub-Saharan Africa 27 April 1929 (Trans-African Routes): The 1920s saw a consolidation of the European hold over Africa as the colonial powers built railroads and made use of advances in automotive and aeronautical technology to create routes across the continent, both to exploit its resources and promote tourism. To achieve these ends, native populations were often forced into work, leading to revolts such as the Kongo-Wara rebellion in French Equatorial Africa.