Why does kennedy refer to irish author frank o'connor's book in his speech?

Kennedy referred to Irish author Frank  O'Connor's book in his speech because to relate his speech conclusion to the things in the book.

Explanation:

To conclude his speech at the dedication at the Aerospace Medical Health Center in San Antonio he refers to frank O'Connor's book He tells in his book how he and his friends would go across the countryside and when they came across and orchard wall that seemed to high to climb they tossed their hats over the wall and they had no choice to follow them.He said,"The nation has tossed it's cap over the wall of space and we have no choice but to follow it."