On August 23 , Obama announced his selection of Delaware Senator Joe Biden as his vice presidential running mate . Obama selected Biden from a field speculated to include former Indiana Governor and Senator Evan Bayh and Virginia Governor Tim Kaine . At the Democratic National Convention in Denver , Colorado , Hillary Clinton called for her supporters to endorse Obama , and she and Bill Clinton gave convention speeches in his support . Obama delivered his acceptance speech , not at the center where the Democratic National Convention was held , but at Invesco Field at Mile High to a crowd of approximately 84,000 people ; the speech was viewed by over 38 million people worldwide
Democratic National Convention
2008 Democratic National Convention
Barack Obama