County, Mississippi) down the Buckatanne River to its confluence with the Pascagoula River, and down the Pascagoula River to a point from the Gulf of Mexico (thought at the time to correspond with the 31st parallel north); and then by a due west line, as far as the Choctaw Nation have a right to grant. The treaty further stated that "none of his Majesty's white subjects should be permitted to settle on the Tombecbee River to the northward of the rivulet called Centebonck" (Santa Bogue Creek in Washington County, Alabama). Although the 1765 treaty encompassed all of what is now Mobile County and a portion of southwestern Mississippi, most of those areas had already been settled during the French Colonial period or were not settled until several decades later in the 19th century. Significant settlement in the Tombigbee River area did not began until the time of the American Revolution, when Loyalists began to arrive in an attempt to escape persecution by Patriots. One of the earliest of these was Thomas Bassett, who reached the Tombigbee settlements in 1772 and received a land grant on the Tombigbee, southeast of modern Leroy, Alabama, from the Crown in 1776 and another at McIntosh Bluff. He was killed in an attack by Native Americans in 1780. The British held West Florida until 1779–81, late in the American Revolutionary War, when it was captured by Spanish forces under the command of Bernardo de Gálvez. It formally became a Spanish possession with the 1783 Treaty of Paris, which also ended the American Revolution. This caused a boundary dispute between the United States (US) and Spain, with the U.S. claiming that the boundary between its territory and West Florida was at the 31st parallel north and Spain claiming it at 32 degrees 28 minutes of north latitude. Spain held the Tombigbee settlements until the Pinckney's Treaty in 1795, in which they agreed to the boundary at the 31st parallel north in return for other concessions by the US. It was ratified in the United States Senate on March 7, 1796, and by Spain on April 25, 1796, being proclaimed on August 3, 1796. The treaty stipulated that both countries would participate in a joint expedition to mark the agreed-upon boundary; President George Washington selected Andrew Ellicott as commissioner. The survey was completed in early 1800, although American settlers had already been pouring into the area since