 Documentation in archives and historical epidemiology demonstrates that governmental policies furthered the progress of this epidemic among the natives, and did little or nothing about the waves of other introduced epidemics.Mean population decline 1774–1874 was about 66%.The name "Seattle" for the city (c. 1853) is an Anglicization of "si'áb" "Si'ahl", the Duwamish and Suquamish chief ("si'áb", high status man).