Peter Salem Letter

This is a document signed by Peter Salem.(...) When I say signed, I mean the "X" between the words Peter and Salem[, a common practice among those without formal education]. He was born into slavery and [after he gained his freedom,] he joined the Massachusetts Minutemen[,] fighting at Concord, Saratoga and most famously [at] Bunker Hill.  Peter Salem went on to serve seven long years, one of the few to do so. He began as a slave, but he died a free American.