Second quote:

Ex-queen Liliuokalani confided to then Senator George Hoar (R. Mass.) that, “The best thing for [Native Hawaiians] that could have happened was to belong to the United States.”

Senator Hoar wrote his own autobiography in 1903 (14 years before the ex-queen died) which included that quote.   "Autobiography of Seventy Years" by George Frisbie Hoar (C. Scribner's Sons, 1903).  To find that quote from Lili'uokalani, look for "Lili'uokalani" in the index to Hoar's book.

See also William Adam Russ, "The Hawaiian Republic" (1894-98) (Associated University Press, London and Toronto 1992).  On page 331, Russ quotes Senator Hoar as quoting those words of Liliuokalani.  

If anyone claims that Senator Hoar was lying, or falsely quoting Liliuokalani, we should note that Senator Hoar was Liliuokalani's strongest ally in the Senate at the time the Treaty of Annexation was introduced in 1897 and the anti-annexation petition was introduced.