Membership in the ANA was restricted to men born in Australia, at a time when the native-born were rising to power in place of an older generation born in Britain. In the 1890s, for the first time, they became the majority of the population. The ANA consisted mainly of energetic middle-class men aged under 50 - a perfect base for a forward-looking, idealistic movement such as federation.
In 1880 the ANA committed itself to the federation of the Australian colonies, and provided much of the organisational and financial support for the Federation Leagues which led the campaign, particularly in Victoria. It avoided party politics, but they soon adopted the rising liberal politician and ANA member Alfred Deakin as their candidate for leadership of the federal movement.
In 1891, when the Victorian Parliament was considering the federation bill, it was the ANA which organised public meetings around the colony to rally support for the bill, many of them addressed by Deakin. After the failure of the 1891 bill, it was the ANA which kept the federal cause alive. When the movement revived after 1897, the ANA campaigned vigorously for the refrendums to approve the proposed constitution.
With federation achieved in 1901, the ANA withdrew from political activity, although it continued patriotic activity such as promoting the observance of Australia Day. It continued to prosper as a private health fund until 1993, when it was absorbed by a larger company, Australian Unity.