This "coffin notice", supposedly written by members of the Molly Maguires, was posted in 1875 in Schuylkill County during the "Long Strike". It was later presented as evidence to the Pennsylvania legislature in 1875 and appears as an appendix to the originally published trial records.
Coffin Notice, print of a drawing, 1875, unknown author; image source: Douglas O. Linder: Famous Trials: The Molly Maguires, https://famous-trials.com/maguire/102-notices.