Henry Howe, Historical Collections of Virginia… (Charleston, SC: William R. Babcock, 1852), 497-498.
WASHINGTON was formed in 1770, from Fincastle county: it is 40 miles long, and 18 broad. This county occupies part of the valley between the Blue Ridge and Clinch mountains, and is watered by the North, Middle, and South Forks of Holston, which rise in Wythe and flow through this county, dividing it into three fertile valleys. Gypsum of a superior quality abounds, and over 60,000 pounds of maple sugar are annually produced. Pop. in 1840, whites 11,731, slaves 2,058, free colored 212; total, 13,001.