America the Beautiful
It may seem as if my suggestion is rather generic in that the song is one that seems like an obvious one to make. However, the third verse, which I note below, has the words "Thine alabaster cities gleam, undimmed by human tears". After 9/11 my church sang the song for weeks at the end of mass and that verse really resonated with me. Every year since then my church has sung that song at the mass on the weekend closest to 9/11 and I have mentioned to my priest how important I think it is to make sure that the third verse is sung prior to him coming down the aisle because I think it speaks to the strength of our country. Thank you for your consideration.
O Beautiful for patriot dream
That sees beyond the years
Thine alabaster cities gleam,
Undimmed by human tears!
America! America! God shed His grace on thee,
And crown thy good with brotherhood
From sea to shining sea!
Mary Catherine Sudiak