In the case of Hawaii, there was no driving need to "populate" the islands with Caucasians. The 1870s and 1880s saw a huge influx of foreign settlers, many of them from the US. According to Robert Schmitt's Demographic Statistics of Hawaii 1778-1965 by 1890, non-Hawaiians comprised 54.9% of the population. That's one of the reasons the US annexed the kingdom, there already was a large population of white Americans living there. Those Americans overthrew the kingdom in 1893 and the nation was annexed in 1898. By then non-Hawaiians comprised 63.8% of the population.