As a traditional country of reception for immigrants, large numbers of Australians never immigrated to North America. In the U.S. census of 2000 and the Canadian census of 2001, 78,673 Americans claimed Australian descent, compared to 25,415 Canadians. Unofficial estimates place the number much higher. As many of these immigrants had either previously immigrated to Australia from somewhere else or were the descendants of immigrants, it is suspected that census data often reflects country of earliest ancestry rather than country of last residence. Australians are spread throughout the United States, with the largest concentration in southern California. They blend easily into mainstream American and Canadian cultures and do not readily join ethnic groups. Australia, the only country occupying an entire continent, covers 2,966,150 square miles, almost as large as the lower 48 states of the United States. Like the North American continent, Australia was lightly populated by native peoples, the Aborigines, when Europeans arrived in the late 18th century. Unlike the United States and Canada, its great distance from Europe and restrictive immigration policies limited population growth. In 2002, Australia’s population was just under 20 million, with 92 percent being of European descent, 6.4 percent of Asian descent, and 1.5 percent of Aboriginal descent. The Dutch explored Australia in the early 17th century but did not colonize it. Captain James Cook’s explorations between 1769 and 1777 led to an English settlement in New South Wales, dominated by convicts, soldiers, and officials. After the American Revolution, with the thirteen colonies no longer available for convict transportation, the British government began to exile convicts to Australia, a policy that led to the forced immigration of 160,000 men, women, and children between 1788 and 1868. By 1830, Great Britain claimed the entire island. In 1901, Australia became a commonwealth and immediately barred almost all “coloreds” from entry. Australia became fully independent of Great Britain in 1937. Since 1973, Australia’s immigration policy has been nonracial. About one-third of immigrants in 2000 were Asian. Australians usually immigrated to North America in pursuit of economic opportunity, beginning with more than 1,000 during the first years after the California gold rush (1848). In 1851, however, most returned when gold was discovered in western Australia. During the 19th century, immigration to the United States averaged less than 1,000 per year. World War II (1939–45) led to a significant rise in immigration, boosted by 15,000 Australian war brides returning with American soldiers who had been stationed there. Between 1960 and 2000, Australian immigration rose as economic conditions at home worsened and fell as they improved, with the annual average at about 4,000. Throughout the 19th and early 20th centuries, there was little immigration from Australia to Canada, in part because of unwritten agreements to avoid competition for immigrants. Data for Australian immigration to Canada are unreliable, but there were only 2,800 Australian-born Canadians in 1941. Immigration began to grow during the 1950s, as working conditions for nurses, academics, and other professionals were similar in both countries, but pay was generally better in Canada. It peaked in 1967, with almost 5,000 Australians entering. As was true throughout the 20th century, however, many came for education or temporary jobs and frequently returned to their homeland. As a result of the 1976 Immigration Act, which made it more difficult to be admitted for work if Canadians could be found to do the job, immigration dropped significantly. Of the 16,030 Australian Canadians in 2001, about 6,400 came after 1980.