There is a long post by Susanne (skw) on the strike and circumstances that led to the poem by Oppenheim, with a comprehensive bibliography, in thread 3742: Bread and Roses

As noted in that thread, The Holt Labor Library credits the music to Caroline Kohlsaat. Words and music (Kohlsaat) are found in: Edith Fowke and Joe Glazer, 1960, "Songs of Work and Freedom," first published by the Labor Education Division, Roosevelt University, pp. 70-71.

The poem was written in 1911, and first published in 'The American Magazine,' Dec. 1911, a month before the Lawrence strike began. The 'Chicago Women Trade Unionists' are credited with the slogan "Bread and Roses" ('The Public,' Oct. 1912).
There are several legends about the song and its use; see the post by Susanne.