Gray, Robert (1755–1806), 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 1789–90 he commanded the Columbia on the first voyage to carry the United States flag around the world. He again circumnavigated the globe in 1790–93. Gray later settled in Boston as a master of coastal vessels.