Short answers, pulled from the story.
First Lady Michelle Obama announced on the 1st of February 2011 that Charlotte had been chosen as the site. The event became the first nominating convention of a major party ever held in North Carolina.
All three days of the convention were held from September 4 through 6, 2012. This marked the first Democratic convention scheduled for only three days since 1948.
Barack H. Obama received 5,556 certified votes representing 100 percent of the ballot. The nomination tally exceeded 2,778 votes after Mississippi delayed its vote so Ohio could give the nomination.
The original platform omitted typical invocations and removed language affirming Jerusalem as Israel's capital. An amendment introduced by former Ohio Governor Ted Strickland sought to reinsert this language but required two-thirds majority for passage.
Charlotte received a $50 million grant from the federal government for convention security. The city spent roughly $25 million on police force including allocations for bicycles software and command center upgrades.