Brownsville is a borough in Fayette County, Pennsylvania, United States, first settled in 1785 as the site of a trading post a few years after the defeat of the Iroquois enabled a resumption of westward migration after the Revolutionary War. The trading post soon became a tavern and inn and was receiving emigrants heading west, as it was located above the cut bank overlooking the first ford that could be reached to those descending from the Allegheny Mountains.