A United States presidential nominating convention is a political convention held every four years in the United States by most of the political parties who will be fielding nominees in the upcoming U.S. presidential election.

The national convention system for nominating presidential candidates was developed by the Democratic Party in the early 19th century. This system was established to provide a more formal and inclusive process for selecting candidates, allowing party members from different states to come together and choose their nominee. The convention system has since been adopted by other political parties in the United States.

"Both major political parties in the United States select their presidential candidates through a process of primary elections. However, voters do not directly select presidential nominees in these primaries. Instead, they choose delegates from their respective states who will attend a national party convention to nominate a presidential candidate for their party." from thisnation.com

1832