At the end of the film, the President, speaking of the sacrifice by Chris and Linda Cronyn, says "the whole earth is their sepulcher". That phrase appears in the Garden of the Missing at the American Cemetery at Colleville-sur-mer above Omaha Beach in Normandy. In the cemetery the full phrase is "Here are recorded the names of Americans who gave their lives in the service of their country and who sleep in unknown graves. This is their memorial. The whole earth is their sepulcher, comrades in arms whose resting place is known only to God."
Among the movie cast members are Willis Bouchey and Morris Ankrum who would go on to be longtime judges on the Perry Mason show.
This movie foresaw the flat panel TV at least 40 years before they were commercially available. The scientist husband and wife main characters had what looked like a 40-inch equivalent over their fireplace and were seen watching the news on it in several scenes. Images on the television set were very accurate matte inserts.
The statue of Christ is "Christ the Redeemer of the Andes," high in the Andes on the border between Argentina and Chile. It was dedicated on March 13, 1904, to celebrate the peaceful resolution of the border dispute between the two countries.