<prompt> Translate the following text to SwahiliBut the demand for whale oil would decline steeply after 1859, with the discovery of oil in Pennsylvania and the start of the American Civil War in 1860.  <response>: Mafuta ya nyangumi yalianza kupungua baada ya uvumbuzi wa mafuta huko Pennsylvania mwaka wa 1859 na kuanza kwa vita vya wenyewe kwa wenyewe mwaka wa 1860. 