Final answer:
The incorrect statement about the election of 1828 is that the two main contenders were both Republicans; in fact, Andrew Jackson represented the Democratic Party with his opponent, John Quincy Adams, representing the National Republican Party.
Step-by-step explanation:
The statement about the election of 1828 that is NOT true is that 'The two main contenders were both Republicans.'
During the 1828 election, Andrew Jackson, who was seen as a champion of the common man and represented the new Democratic Party, competed against John Quincy Adams, who was associated with the National Republican Party. Hence, they were not both Republicans. This election revealed a shift in political power toward new states west of the eastern seaboard and Jackson's victory signified the end of the older politics of deference, ushering in an era where political authority appeared to rest with the majority. The election also illustrated the emergence of a new political organization where loyalty to the party was paramount. The use of negative campaign tactics by Jackson's team and the depiction of Jackson as a hero of the common man were also characteristics of this election.