Does anybody familiar with Janis Joplin know this song and its ties to a movie?

Janis Joplin's song "Bobby Mcgee", there was an old movie with Sissy Spasick in it that was a true story and one of Janis Joplins songs were the theme song to the movie. It is a true story and I dont know the name of the movie, but Im pretty sure the song was "me and bobby mcgee" The story starts and ends around this bridge, if that helps.