On April 25, 2013, I took the oath to become a citizen of the United States. Perhaps only those who have taken this oath can fully understand how I felt that afternoon in Boston. I felt a strong sense of belonging, and tears welled up in my eyes more than a few times during the hourlong ceremony.

I have no reason to doubt that the 1,834 other men and women who took the oath with me also felt that special sense of homecoming. On that sunny afternoon, it seemed unreal that just 10 days earlier, another new citizen of this country...