Sentence 2 This was around the time that the United States men’s ice hockey team shocked the world by winning the gold medal in the Winter Olympics in Lake Placid.
The purpose of this paragraph is to show how Dr. Farrow and Mrs. Lane created an arboretum and save a grove of Sycamore trees. Sentences 1, 3, 4, and 5 all add to the purpose of the paragraph. Sentence 2, however, talks about the US men's ice hockey team winning the gold medal. This win had nothing to do with the arboretum or saving the Sycamore trees. While interesting, it does not belong in this passage.