Nelson Mandela is considered one of the most influential people in the world. With him passing away, he really left his mark on the world he lived in. President Obama visited the cell Mandela was held captive in for 18 of his 27 years serevd in prison. During his visit, Obama was very touched by just being in the presense of where Mandela was kept captive. Nelson Mandela will forever be viewed as one of the strongest, most influential men that ever lived.