cherubrock74

Yes I know they have all the information already and I am sure they will ask at the interview.
Will mention it in my application and just tell what happened.

Thanks for the quick reply SK2014!

21 years ago I was denied entry at the airport because I was told I needed a fiance visa to enter and get married and could not enter under the visa waiver program.
Obviously I never knew of a fiance visa. I left the same day.

I have been permanent resident since 2010
 

Under the N400 it asks:
 

Have you EVER been removed, excluded, or deported from the United States?
Have you EVER been ordered removed, excluded, or deported from the United States?
Have you EVER been placed in removal, exclusion, rescission, or deportation proceedings?

If yes I can explain what happened.
 

After I was denied entry I just had to wait for the my visa to be processed I was never given a certain time before I would be allowed to re-enter the US  or things like that.

Should I mention the incident in my application?

If yes what is the difference between ever been removed, ordered removed or placed in removal? Meaning under which question I should add my yes and explain?