In 1932 Governor-General Lord Bledisloe gifted the Treaty House and grounds at Waitangi to the nation. He hoped that the site would become a national memorial, symbolising that the Treaty of Waitangi had initiated a unique relationship between the indigenous and the colonising peoples.
The arrest in 1916 of prophet Rua Kenana followed the last instance of armed Maori resistance to Pakeha. Rua established a community at Maungapohatu in the Ureweras that attracted Maori disgruntled with the Pakeha system. Rua had discouraged recruitment for the First World War and broke prohibition laws by selling alcohol. An expedition made its way into the Ureweras and, after a gunfight in which Rua's son died, the prophet was arrested. The judge at Rua's trial for sedition told Rua his 18-month sentence for resisting arrest was 'the lesson your people should learn from this trial'.
The 1970s brought major changes for Waitangi Day. The day finally became a public holiday. Increasingly, it also became the focus of growing Maori protest about the status of the Treaty of Waitangi and issues of race.
Concerns over land and other matters continued to be voiced by Maori in the 1980s. The call was for greater Pakeha awareness and acceptance of Maoritanga, seen as guaranteed by the Treaty, and for acknowledgement of Maori as the tangata whenua (people of the land).
Maori were suspicious of the government using the Treaty as the unifying symbol of the emerging multicultural society. This was a way, it was suggested, of avoiding grappling with Treaty problems and the bicultural partnership. Maori opinion was divided, both on Treaty issues and on Waitangi Day events. Activists called for a boycott of Waitangi Day until the terms of the Treaty were honoured, but there was no unified response.
Waitangi Day events became a focus for protests about sovereignty in the 1990s. Maori sovereignty – defined over the years in various ways as mana motuhake, autonomy, self-determination or self-regulation – has been one of the most enduring Maori understandings of the Treaty's second article (in which te tino rangatiratanga was not ceded but guaranteed).
New Zealand marked the 150th anniversary of the signing of the Treaty of Waitangi in 1990. The 1990 Commission, in charge of co-ordinating and promoting activities for the sesquicentennial year, was convinced that the Maori–Pakeha partnership concept had to be broadened to embrace the many cultures of the nation. The Treaty and Waitangi Day had their place, but they were not the only factors in the national identity equation.
In 2000 Prime Minister Helen Clark was reported as saying that 'It is my strong belief that the days and events around Waitangi Day should contribute to the building of a sense of New Zealand identity and purpose.' In the 21st century the day has been linked more closely with New Zealand identity, and events have expanded beyond Waitangi itself. Protests have continued, and representatives of the Crown have not always been present at Waitangi.