For more than a century immigration policy has been concerned with two major issues: assimilability and employability. Would immigrants fit into existing society without friction and would they be gainfully employed for their own and society's benefit? These two concerns were obviously related. If suitable employment were not available, then immigrants could not fit into society. If immigrants took away jobs from the native-born or lowered wages and standards, then they would not be readily accepted. Racial features could prevent non-Europeans from being tolerated, as might their differing cultures and languages. But economic viability was also essential.

It was rarely argued that there was no further room in Australia for an increased population. The often quoted national anthem theme from the 1870s was that ‘for those who come across the seas we've boundless plains to share’. The Millions movement of the 1920s enthusiastically looked to fill the empty spaces. This optimism collapsed along with the world economy in 1929 and the drift to the cities became an avalanche. But optimism revived during the Second World War. Its lasting monument was the Snowy Mountains scheme, built largely with immigrant labour from the late 1940s. This not only produced hydro-electricity but also allowed irrigation along the Murrumbidgee and Murray. Many who settled in these areas were immigrants from southern Europe. Australia applied more of its water supply to irrigation than any other developed country, with consequent salination problems.