But when her husband Bob died in 1949, Cooper decided it was time to leave her Northland home and join the growing number of Māori heading to urban centres. She moved her children to Grey Lynn in Auckland and once again turned her focus to social activism.
In 1951, she was elected the first president of the Māori Women's Welfare League, which played a major role in improving Māori living conditions in urban areas. Cooper led the charge to clear the slum-like conditions forming in Auckland and fought racial discrimination in housing, employment and education.
In 1974, having worked tirelessly to improve the lives of hundreds of Māori, Cooper announced she was stepping down from public life. Little did she know that just a year later, she would become the figurehead of the most significant Māori protest in history.
On September 14, 1975, 80-year-old Cooper set out on a dusty Far North road with Wellington as her destination.
The walk stemmed from concerns over the continuing alienation of Māori land. She was supported not only by the walking stick clutched in her hand but also by the rally of marchers behind her crying: "Not one more acre of land to be lost."
The hikoi began with just 50 protesters but numbers swelled as they stopped at local marae and by the time Cooper reached Wellington, she was joined by 5000 marchers and had the nation's undivided attention.
Cooper spoke at 25 marae along the way, gaining more than 60,000 signatures petitioning the Government to repeal all statutes that allowed land to be taken from Māori.
Cooper's strength and eloquence left a lasting impression on the country, with the press dubbing her "Mother of the Nation". Cooper believed in a world where Māori and Pākeha lived in harmony, as equals, and regularly repeated this message: "Let us remember that the Treaty was signed so that we could all live as one nation in Aotearoa."
When Cooper died in 1994, aged 98, she was mourned by Māori and Pākeha alike. Her televised funeral service saw more than a million New Zealanders tune in to farewell the wahine toa.
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