The first night will be devoted to Barack Obama's personal story. His wife, Michelle, is the keynote speaker. She visited the convention hall today to become familiar with the speakers' platform.
The evening is expected to be quite emotional.
Senator Ted Kennedy, who is battling brain cancer, is in Denver and plans to be at Pepsi Center to watch a video tribute to him. An official says Kennedy may address the convention if he feels up to it.
Obama's campaign is dismissing concerns about the impact of die-hard Hillary Clinton supporters on the choreographed show of unity.
Meanwhile, Obama's running mate, Senator Joe Biden, is headed to Denver. Before leaving Delaware, he made a surprise visit to the train station he uses for his daily commute to Washington, calling everyone there his "family."