<P> Many who went were between the ages 12 and 24 . Between 1860 and 1870, the U.S. population increased by seven million; about 350,000 of this increase was in the Western states . </P> <Table> Census Population of western States <Tr> <Th> State </Th> <Th> 1870 </Th> <Th> 1860 </Th> <Th> Difference </Th> </Tr> <Tr> <Th> California </Th> <Td> 560,247 </Td> <Td> 379,994 </Td> <Td> 180,253 </Td> </Tr> <Tr> <Th> Nevada </Th> <Td> 42,491 </Td> <Td> 6,857 </Td> <Td> 35,634 </Td> </Tr> <Tr> <Th> Oregon </Th> <Td> 90,923 </Td> <Td> 52,465 </Td> <Td> 38,458 </Td> </Tr> <Tr> <Th> Colorado </Th> <Td> 39,684 </Td> <Td> 34,277 </Td> <Td> 5,407 </Td> </Tr> <Tr> <Th> Idaho </Th> <Td> 14,990 </Td> <Td> − </Td> <Td> 14,990 </Td> </Tr> <Tr> <Th> Montana </Th> <Td> 20,595 </Td> <Td> − </Td> <Td> 20,595 </Td> </Tr> <Tr> <Th> Utah </Th> <Td> 86,789 </Td> <Td> 40,273 </Td> <Td> 46,516 </Td> </Tr> <Tr> <Th> Washington </Th> <Td> 23,955 </Td> <Td> 11,594 </Td> <Td> 12,361 </Td> </Tr> <Tr> <Th> Wyoming </Th> <Td> 9,118 </Td> <Td> − </Td> <Td> 9,118 </Td> </Tr> <Tr> <Th> Totals </Th> <Th> 888,792 </Th> <Th> 525,460 </Th> <Th> 363,332 </Th> </Tr> </Table> <Tr> <Th> State </Th> <Th> 1870 </Th> <Th> 1860 </Th> <Th> Difference </Th> </Tr> <Tr> <Th> California </Th> <Td> 560,247 </Td> <Td> 379,994 </Td> <Td> 180,253 </Td> </Tr>

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