What literary device is used in the following sentence? " i tried to hold it back, but a wave of emotion overcame me."

The poetry device used here is metaphor.

Metaphor is a poetry device that is used in comparing two unlike things without using words like 'like' or 'as'.

The phrase 'a wave of emotion' is metaphorical because the emotion that is felt at that time is compared to that of a wave without including words such as  'like' or 'as'.

Therefore it is a metaphor.

Hope it is clear ^_^

the president was the speaker and it was a great part of history.

explanation:

video of the national aeronautic space administration's (nasa) coverage of president john f. kennedy’s address at rice university, houston, texas, concerning the nation's efforts in space exploration. in his speech the president discusses the necessity for the united states to become an international leader in space exploration and famously states, "we choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard."

did you ever figure it out?