The 2008 Maryland Democratic presidential primary took place on February 12, 2008. Nicknamed the "Potomac Primary" or the "Chesapeake Primary" because the District of Columbia and Virginia also held their primaries that day (and all three border the Potomac River), a total of 70 delegates were up for grabs in Maryland. The winner in each of Maryland's eight congressional districts was awarded all of that district's delegates, totaling 46. Another 24 delegates were awarded to the statewide winner, Barack Obama. The 70 delegates represented Maryland at the Democratic National Convention in Denver, Colorado. Twenty-nine other unpledged delegates, known as superdelegates, also attended the convention and cast their votes as well.