Number two is probably Frost's Mending Wall and "Good fences make good neighbors."
"Before I built a wall I’d ask to know
What I was walling in or walling out,
And to whom I was like to give offense."
Only poem I can cite by heart a quarter of a century after spending time with it in school.
Probably depends on the audience. Readers of the New Yorker or who have taken courses from Ivy League English professors are probably different from the random person on the street (who is even vaguely familiar with the poem).