<Tr> <Td_colspan="2"> History </Td> <Td> </Td> </Tr> <Tr> <Td> </Td> <Td> Oregon Treaty </Td> <Td> June 15, 1846 </Td> </Tr> <Tr> <Td> </Td> <Td> Organized </Td> <Td> August 14, 1848 </Td> </Tr> <Tr> <Td> </Td> <Td> Washington Territory split off </Td> <Td> March 2, 1853 </Td> </Tr>

Who did the us buy the oregon territory from