The Lea family was among the largest flour mill operators at the Brandywine Falls, near Wilmington, Delaware, since the 1770s, when Thomas Lea (1757–1823) joined in partnership with Joseph Tatnall (1740–1813) to operate mills on the north bank of the stream. This small collection of Lea family papers documents Delaware and Pennsylvania land use and ownership, elite family and social relationships, and agricultural business operations from the early eighteenth century to the mid-nineteenth century. The materials are from four generations of the William Lea (1805-1876) family lineage. The collection is arranged into four series: Real estate and financial papers, Correspondence, Personal papers, and Newspaper clippings.