Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

After repeated efforts by the Samoan independence movement, the New Zealand Western Samoa Act 1961 of 24 November 1961 granted Samoa independence effective 1 January 1962, upon which the Trusteeship Agreement terminated. Samoa also signed a friendship treaty with New Zealand. Samoa, the first small-island country in the Pacific to become independent, joined the Commonwealth of Nations on 28 August 1970. While independence was achieved at the beginning of January, Samoa annually celebrates 1 June as its independence day.
What act gave Samoa independence?