Federation in 1901 was the culmination of a growing sense of national identity that had developed over the latter half of the 19th century, as seen in the works of the Heidelberg School painters and writers like Banjo Paterson, Henry Lawson and Dorothea Mackellar. The World Wars profoundly altered Australia's sense of identity, with World War I introducing the ANZAC legend, and World War II seeing a reorientation from Britain to the United States as the nation's foremost ally. After the second war, 6.5 million migrants from 200 nations brought immense new diversity. Over time, the diverse food, lifestyle and cultural practices of immigrants have been absorbed into mainstream Australian culture.