In the original version of the song, Bobby is a woman; Janis Joplin, who was a lover and a friend of Kristofferson's from the beginning of her career to her death, changed the sex and a few of the lyrics in her cover. Kristofferson states he did not write this song for her, but the song is associated with her. Especially, he has said, in the line, "Somewhere near Salinas, Lord, I let her slip away."
http://tabs.ultimate-guitar.com/j/janis_joplin/me_and_bobby_mcgee_ver2_crd.htm
