Final answer:
The first candidate to run for president under the newly formed Democratic Party was Andrew Jackson.
Step-by-step explanation:
The first candidate to run for president under the newly formed Democratic Party was Andrew Jackson. He was nominated as the party's candidate and ran in the presidential election of 1824, which was the first election held after the formation of the party. Although Jackson won the popular vote, he did not receive enough electoral votes to secure a majority, and the election was decided by the House of Representatives.
Learn more about Democratic Party's first presidential candidate