Holt and Johnson developed a personal friendship. They were the same age, and had first met in 1942, when Johnson visited Melbourne as a naval officer; afterwards they shared a similar career trajectory. Holt visited the U.S. twice while in office, in June and July 1966, and on the latter visit was invited to stay at Camp David. He and Johnson reportedly played tennis, lounged by the pool, and watched movies together. In October 1966, Johnson made the first visit to Australia by an incumbent American president; Vice President Hubert Humphrey had visited in February of that year. He toured five cities, and was greeted by large crowds as well as a number of anti-war demonstrators, who disrupted the presidential motorcade. The opposition criticised the visit as a publicity stunt. Johnson later returned to Australia for Holt's memorial service, and invited his widow Zara to stay with him when she visited the United States in 1969.