“American Scrapbook: A Celebration of Verse,” at the Kennedy Center, is a tribute to the favorite poetry of the Kennedy family. It is based on poems selected by Caroline Kennedy for her books, “The Best-Loved Poems” of Jacqueline Kennedy Onassis and “A Family of Poems: My Favorite Poetry for Children,” and is part of the 50th Anniversary Celebration of John F. Kennedy’s presidency. But “American Scrapbook” pays honor to poetry itself, to its depth and breadth, its ability to provoke humor or sadness, its relationship to music and dance. Last of all, the production is an homage to specific poets and particular poems, which are divided into four general categories: reflections, nature, civil rights and America.