The Hoover Brothers mill (also known as the Hoover-Seago mill, according to a Texas Big Sandy Project map), was located in Upshur County in 1854 just across the Big Sandy Creek from Chilton on the Seago Crossing. The water-powered mill was established as early as 1848 or 1849. This sawmill and grist mill operation, enumerated as “Hoever and Hoever” during the 1860 census, was d a capital investment of $4,000, with $1,000 invested in the sawmill and $3,000 in the grist mill. Raw materials included $250 worth of logs, $7,800 worth of corn and $2,600 worth of wheat. Two men were employed in the sawmill at a total monthly wage of $40 and one man in the grist mill at $20 monthly. The operation manufactured 300,000 feet of lumber valued at $3,000, and milled 7,800 bushels of cornmeal valued at $7,800 and 520 bushels of flour worth $2,860.
By 1866, Colonel Eli M. Seago controlled the sawmill as an adjunct to his store. He was succeeded by Alvin Seago no later than 1880. In 1903, the operation was known as the Seago Box Manufacturing Co. A mechanic lien filed against Seago Box Manufacturing company that year revealed that it was located about three miles from Big Sandy on the south side of Big Sandy Creek.