Christianity has had an enduring impact on Australia. At the time of Federation in 1901, 97% of Australians professed to be Christians. The Anglican Church (formerly Church of England) remained the largest denomination until 1986, when it was surpassed by the Roman Catholic Church. Australian Catholics were predominantly of Irish origin until post-World War II immigration brought more than a million Catholics from elsewhere in Europe. The Christian festivals of Christmas and Easter are national public holidays in Australia. Christian charitable organisations, hospitals and schools have played a prominent role in welfare and education since colonial times. In 2008, 20% of total students attended Catholic schools. Christian organisations such as the St. Vincent de Paul Society, the Salvation Army and Anglicare provide social services throughout Australia. Historically significant Christians include preachers David Unaipon, the first Aboriginal author, and the Reverend John Flynn, who founded the Royal Flying Doctor Service. Suffragette Catherine Helen Spence was not only Australia's first female political candidate, but also one of its first female preachers. Mary MacKillop, who co-founded an order of nuns in the 19th century, called the Sisters of St. Joseph, became the first Australian to be canonized as a Catholic Saint in 2010, and Sir Douglas Nicholls, a preacher and Aboriginal rights activist was the first indigenous Australian to be appointed Governor of an Australian State.