SOTU: Unforgettable State Of The Union Speech Moments (PHOTOS)

All eyes will be on President Barack Obama Tuesday evening, when he gives his third official State of the Union address. For many presidents, the annual address to Congress has been an opportunity to change the national conversation and bring new platforms to the forefront. Some of the United States' most enduring policies, from the Monroe Doctrine in the 1820s to the Great Society in the 1960s to the "Axis of Evil" in the 2000s, were first iterated at these addresses.

In recent years, responses to the address have often made as much news as the actual content of the speeches. When members of Congress and other high-profile political figures in the audience heckle, boo, or even fall asleep, it can be just as newsworthy as a new policy initiative.

Here's a look back at some of the most memorable moments in SOTU history: