If you saw this film before the restoration that was released in 1986, you owe yourself another viewing. The film was severely cut by the studio in both 1937 and in 1942, deleting a lot of information on the motivations of the the secondary characters. It was those expurgated versions that made their way to television in later years. Though some of the filmed footage is lost, a soundtrack of the full film was discovered in 1973; using still photographs, the American Film Institute was able to reconstruct the film according to director Frank Capra's original vision. The DVD version of the film also includes an alternate ending to the film (which was thankfully eliminated from the film early one) - Capra's ending is far better (this article from the AFI Catalog goes into more detail on the film's production, and this article in the Chicago Tribune gives a more complete outline of the scenes that were added to the restored version).
James Hilton based his tale of Shangri-La on another legendary location - the mythical Tibetan city of Shambala. This article from PBS's In Search of Myths and Heroes will provide a little more information on Hilton's inspiration for the place of perfect harmony. Principle photography on the film ran from March 23 to July 17, 1936, and in the months before and during production, Germany occupied the Rhineland, and Italy invaded Ethiopia. With Hitler beginning his reign of terror, it was becoming apparent to Europeans - and to Americans - that another war was in the offing. Though written by Hilton between the wars, by the time the film was released in 1937, Robert's despair of a world gone mad was perfectly relate-able to the contemporary audience.
The character of George, as portrayed by John Howard, is an interesting one. George has spent his life reflecting in his brother's glory; were he to stay in Shangri-la, his one source of self-esteem - that of being the great Robert's brother - would be gone. At first, it's easy to sympathize with George; the group is being lied to, and he is more than angry at being held against his will. But Howard brings George's resentment to a fever pitch. Ultimately, it's hard to like him - he claims to be in love with Maria, but his actions don't speak of love - they display his willingness to use any means or any one to get out. John Howard does an excellent job of creating a character that has no self esteem, but much pride.
Sam Jaffe, who portrays the High Lama, was 46 when this film was released, and this was only his third feature film. His career began in the Yiddish theatre; during the period from 1918 to 1937, he appeared in 14 Broadway plays, including The Jazz Singer and Grand Hotel. He was actually the third choice for the role of the High Lama - the first two choices (A. E. Anson and Henry Walthall) both died before filming began. This TCM article provides more detail on the early casting of the film. Two years after this Lost Horizon, Jaffe starred in the title role in Gunga Din (1939). He later appeared in such notable productions as The Asphalt Jungle (1950) and The Day the Earth Stood Still (1951), but by 1955, he was blacklisted after he refused to name names to HUAC. His greatest fame occurred in television, when he appeared as Ben Casey's mentor, Dr. Zorba, in Ben Casey. Married twice (his first marriage to Lillian Taiz ended with her death in 1941. His second was to the actress Bettye Ackerman - who appeared as Dr. Maggie Graham in Ben Casey), he continued acting until his death in 1984 (aged 93).
Another actor whose fame came primarily from television was the lovely Jane Wyatt, who appears as Sondra, the young woman who encourages the High Lama to bring Robert Conway to Shangri-La. While this was not her first film, it was probably her most notable one. For the most part, Ms. Wyatt was relegated to starring roles in B movies. By the 1950s, she had switched over to television, where she became best known for her role as Margaret Anderson in Father Knows Best (1954-1960). She would create the role of another important mother when she appeared as Spock's human mother, Amanda in the episode Journey to Babel in Star Trek - a role she would reprise in Star Trek: The Voyage Home (1986). She was one of the many performers who went to Washington, DC in 1947 to protest the HUAC hearings. She continued acting until 1992 (her final role was as older Vicki in The Young Indiana Jones Chronicles). Married for 65 years, Ms. Wyatt died in 2006, at the age of 96.
Lost Horizon was remade as a musical in 1973, with Peter Finch as Conway, Michael York as George, and Charles Boyer as the High Lama. With not a singer in the bunch, the film was not especially noteworthy.
We'll leave you with a trailer from the film, and a strong recommendation to see it: