This is a Jefferson 14″ Backsaw sold by Sargent. Their designated #41.
I’ve Lightly cleaned and sharpened this.
According to Hand-Saw makers of North America (Erwin L. Shaffer) Sargent sold saws by several saw makers–e.g. Disston, Simons, E.C. Atkins and C.E. Jennings.
I believe this one was from the Disston Jackson line.