The Washington County Railroad was chartered to construct a line of railroad from Hempstead to Brenham, TX (the county seat of Washington County). Construction of the line started in June of 1858, at a connection with the Galveston and Red River Railroad in Hempstead, westward toward the Brazos River, 6.6 miles distant, and finally reaching that river in April of 1859 (thus averaging only a little over one-half mile per month). Meanwhile, construction had also started on the other side of the Brazos in Chappel Hill, eastward. Despite no bridge in place over the Brazos, operations begain in 1860, with a car ferry in use across the river; a bridge replaced the ferry in 1861. Tracks from Chappel Hill westward eventually reached Brenham in April of 1861, thus completing the WCRR.

The WCRR was sold to the Houston and Texas Central Railroad in 1869 (having also purchased the G&RR through Hempstead), who extended it westward from Brenham to Giddings (also abandoned) and further west to Austin, the state capital. Ownership changed hands again with the Texas & New Orleans Railroad taking over in 1927, itself a subsidiary of the mighty Southern Pacific Railroad, who ultimately abandoned the former Washington County Railroad in 1961-62.