mudsill

noun3

1. •
   The lowest sill of a structure, usually placed in or on the ground.
2. •
   (figurative) A particularly low or dirty place/state; the nadir of something (see rock bottom)

   • The Pre-Historic Era was the mudsill of human development.
3. •
   (Southern-US, old-fashioned) A person of low status or humble provenance.

   • We were now miserable mercenaries, serving for low pay and rough rations. Read the Southern papers and you will see us described. “Mudsills,” — that, I believe, is the technical word. — 1861