Native Americans in the United States reached the West Coast in the 1770s, smallpox rapidly killed at least 30% of Northwest Coast Native Americans. For the next eighty to one hundred years, smallpox and other diseases devastated native populations in the region. Puget Sound area populations, once estimated as high as 37,000 people, were reduced to only 9,000 survivors by the time settlers arrived en masse in the mid-19th century. Smallpox epidemics in 1780–82 and 1837–38 brought devastation and drastic depopulation among the Plains Indians. By 1832, the federal government established a smallpox vaccination program for Native Americans ("The Indian Vaccination Act of 1832"). It was
Dutch Americans settlers from those countries arrived since the 1850s after California had statehood. They drained away swamps and created artificial islands known as polders, constructed dikes to back away the Sacramento and San Joaquin Rivers flowing into the San Francisco Bay, also turned them into fertile farmlands and set up inland ports such as Stockton. Also their communities like Lathrop, Galt, Rio Vista and French Camp which were named for Belgians from Belgium are of both French (Walloon) or Flemish origin. Not included among Dutch Americans are the Pennsylvania Dutch, a group of German Americans who settled in Pennsylvania in the