The correct answer to this open question is the following.
Unfortunately, you did not attach the underlined sentence on page 2. Without that information, we don't what are you talking about.
However, trying to help you we did some research and can say that the idea that Kennedy repetition of the wording "not to our but to our" empathize that Frost made contributions that were distinct from those typically recognized in America.
We are talking about the speech delivered by the United States President John F. Kennedy in Amherst College on October 26, 1963. During his speech, President Kennedy honored the life and contributions of American artist and poet Robert Frost (1874-1963) who made important contributions to promote Massachusetts's rural area.