Florence Reese (April 12, 1900 – August 3, 1986) was an American social activist, poet, and folksong writer. Born in Sharps Chapel, Tennessee the daughter and wife of coal miners, she is best known for the song, "Which Side Are You On?" written in 1931 during a strike by the United Mine Workers of America in which her husband, Sam Reece, was an organizer.

http://en.wikipedia.org/wiki/Florence_Reece
http://en.wikipedia.org/wiki/Which_Sid...