Gray, Robert (17551806), a United States sea captain and fur trader. In 1792. while sailing along the Pacific coast, he discovered the Columbia River and named it for his ship. His discovery helped the United States later to establish its claim to the Oregon territory. Gray was born in Tiverton, Rhode Island. During 178990 he commanded the Columbia on the first voyage to carry the United States flag around the world. He again circumnavigated the globe in 179093. Gray later settled in Boston as a master of coastal vessels.Captain Robert Gray discovered and named the Columbia River in Oregon.