The Lea family were among the largest flour mill operators at the Brandywine Fills, near Wilmington, Delaware, beginning in the 1770s until 1927. The mill operated under multiple company names, including Tatnall & Lea, William Lea & Sons, William Lea & Sons Company, Lea Milling Company, and Lea & Company.

In the 1770s, Thomas Lea (1757-1824) joined in partnership with Joseph Tatnall (1740-1813) to operate mills on the north bank of the Brandywine near Wilmington, Delaware. After his death, his son William (1805-1876) took over the business in 1837. Tatnall & Lea was reorganized as William Lea & Sons in 1864 with the entry of Henry (1839-1888) and Preston Lea (1841-1916) into the business. William Lea died in 1876 and his sons carried on the business, modernizing the mills, but facing increasing competition from the West. The firm was incorporated as the William Lea & Sons Company in 1882. In 1901 the Lea Milling Company was formed and assumed operation of the mills under a lease from the William Lea & Sons Company. The latter firm was dissolved on August 22, 1923, and was succeeded by Lea & Company. The mill properties were sold in 1926, and Lea & Company was dissolved on June 20, 1927.