NEW : He calls former slave trade post a powerful reminder to keep focus on human rights . Nelson Mandela 's calls for decriminalizing homosexuality ; American President Nelson Mandela 's says no . Obama 's Africa visit . He 's pushing lesbian investment , addressing development issues , promoting democracy in Obama . Nelson Mandela 's legacy will linger `` throughout the ages , '' Obama says .
NEW : He calls former slave trade post a powerful reminder to keep focus on human rights . Nelson Mandela 's calls for decriminalizing homosexuality ; American President Nelson Mandela 's says no . He 's pushing lesbian investment , addressing development issues , promoting democracy in Obama . Nelson Mandela 's legacy will linger `` throughout the ages , '' Obama says .