What is the significance of the 2008 election?

It was the first election of a U.S. President whose ancestry is half European/ half African.

It was the first time that a Democratic presidential candidate received more than 50% of the nationwide popular votes since Jimmy Carter did in 1976, and it was the first time that a Democratic presidential candidate both received more than 50% of the nationwide popular votes and carried more than 50% of the states since Lyndon Johnson did in 1964.

It was also the first U.S. presidential election since 1952 in which neither the incumbent President nor the incumbent Vice President was a candidate.