The state takes its name from the Ohio River. The name originated from the Iroquois word ohi-yo', meaning "great river" or "large creek".[21][22][23] Partitioned from the Northwest Territory, the state was admitted to the Union as the 17th state (and the first under the Northwest Ordinance) on March 1, 1803.[10][24] Ohio is historically known as the "Buckeye State" after its Ohio buckeye trees, and Ohioans are also known as "Buckeyes".