Woman's plaid shawl

Civil War era woman's plaid shawl of single ply wool woven in a 2/2 twill. Twisted self fringe on three sides, fourth side has fringe missing. Reddish color of wool appears to be dyed with madder root. Greenish threads look yellowish under microscope. Dark thread looks like indigo under microscope,

Year (or year range)
1860-1870
Approximate era
1851-1900