I am trying to find out the name of an old movie. I saw it when I was young and would like to find it again. I am guessing it was made some time between 1945 and 1965. All I remember was a little girl walking along a railroad track with her rag doll and she was singing a song ( something about "buy me a rainbow...") It seems to me that it was similar in style to "To Kill a Mocking Bird". I believe the title might have had to do with a swing... back yard swing... front porch swing..

Please Help!

This is a wag, and is probably wrong.

This Property Is Condemned (1966)
starring Natalie Wood, Robert Redford, Mary Badham (The girl who sings the song, she earlier starred in "To Kill a Mockingbird".), Charles Bronson, Kate Reid
IMDb synopsis:
Willie Star narrates the story about her sister, Alva, flirtatious attraction of the town of Dodson, Mississippi. Her mother uses Alva's charms to meet the family's needs, so to speak. Then, railroad official Owen Legate arrives in Dodson, Mississippi, to shut down much of the town's railway, the main source of income. Legate and Alva are attracted to each other, but he doesn't like the family's values. Alva challenges her mother by getting drunk and openly flirting with her mother's boyfriend, furthering her journey to a tragic ending.

This Property Is Condemned (1966) - IMDb

Here's the movie trailer:
http://www.youtube.com/watch?v=5JX84nAZDX4

Here's the song:
http://www.youtube.com/watch?v=O1Uw5hptVEE