William Barr, early Nacogdoches merchant, was born in Londonderry, Ulster County, Ireland, around 1760, the son of John and Inez (Gibson) Barr. When he was twelve, his parents took him to Pennsylvania, where they lived first in Philadelphia and later in Pittsburgh. After serving three years as a captain in the United States Army, Barr moved to the Spanish province of Louisiana, about 1786. In 1787 he took the oath of allegiance to Spain before Governor Esteban Miró and in 1793 moved to Nacogdoches, Texas. In 1798 Barr associated himself with Luther Smith, Edward Murphy, and Peter Samuel Davenport in a commercial firm later known as the House of Barr and Davenport. In 1800 the Spanish government gave Barr a commission to supply the Indians in Texas with certain presents and to trade with them for pelts, furs, and livestock. In this capacity he operated until his death, in 1810. His estate in Natchitoches alone was appraised at $156,945. Barr, who never married, left part of his estate to his mother and two sisters and part to Davenport.