From the label:

“Spinnerin Deluxe 4 Ply (Knitting Worsted Weight)
4 ozs. Net Weight. 100% Orlon Acrylic
Machine Launderable, Non Pilling, Anti-Stretch.
Wash-Fit”

Label indicates yarn was manufactured by the Spinnerin Yarn Co, Inc., South Hackensack, N.J. 07606