During the second half of the 19th century Māori generally lost control of much of the land they had owned, sometimes through legitimate sale, but often due to unfair land-deals, settlers occupying land that had not been sold, or through outright confiscations in the aftermath of the New Zealand Wars. In the period following the New Zealand Wars, the New Zealand government mostly ignored the treaty, and a court-case judgement in 1877 declared it to be "a simple nullity". Beginning in the 1950s, Māori increasingly sought to use the treaty as a platform for claiming additional rights to sovereignty and to reclaim lost land, and governments in the 1960s and 1970s responded to these arguments, giving the treaty an increasingly central role in the interpretation of land rights and relations between Māori people and the state. In 1975 the New Zealand Parliament passed the Treaty of Waitangi Act, establishing the Waitangi Tribunal as a permanent commission of inquiry tasked with interpreting the treaty, researching breaches of the treaty by the Crown or its agents, and suggesting means of redress. In most cases, recommendations of the Tribunal are not binding on the Crown, but settlements totalling almost $1 billion have been awarded to various Māori groups. Various legislation passed in the latter part of the 20th century has made reference to the treaty, which has led to ad hoc incorporation of the treaty in law. Nonetheless, the treaty has become widely regarded as the founding document of New Zealand.