…compared to the United States?
Both countries have vast land areas, many natural resources, successful democracies (more than we can say at the moment), healthy economies, and the same benefits of the British legal tradition. Yet Canada has just 35 million people and Australia barely 25 million, while the US has ten times as many.
Is there a historical reason? Political? Better weather?
First US census(1610), population: 350
200 years later (1810), population 7,239,881
First Australian census(1788), population: 859
200 years later (1988), population: 16,687,082
Why is the population of the US growing so slowly (compared to Australia)? Are there some historical or political reasons for this? 
And how much of those vast land areas is habitable, compared to the U.S.?
The problem is obvious… Same reason Siberia or the Gobi desert or Sahara are sparsely populated. Something like 90% of Canadians live within 100 miles of the USA border. The majority of Canada is rocky and too cold for agriculture, the majority of Australia is big red desert. Most Australians live along the east coast and southeast tip… The center is barely habitable. Despite modern tech. The majority of population lives where they can grow food, and total population tends to mirror the food capacity of the country. (IIRC one of the most densely countries is Netherlands, but it’s incredibly fertile everywhere.).
The same is true of most countries - even China has vast areas that are not very habitable; the Midwest and west USA are much less populated than the east coast or California. The difference is that so much more of Canada and Australia are not arable.
Quite a lot more of it than is generally inhabited now, that’s for sure. Aboriginal cultures in both countries have inhabited the “uninhabitable” areas from long before anyone else got there.
Less living space in Canada.
That may sound paradoxical, given our size, but it’s true.
In the US, you were able to have communities all along the eastern seaboard, with gradual westward settlement - by generational leaps. Some people would move west, settle down, raise families, and then their young’uns could move further west and repeat the process. Yes, there were mountains and rivers to get through, but there was arable land, of varying quality, of course, all through the area.
Contrast that to Canada. The Canadian Shield is 1,000 miles of rock. No arable land. That kind of leap-frogging settlement wasn’t possible. The North-West could only be settled once there was a strong enough government to provide the money for a railway to punch its way though to the Prairies.
Then there’s our climate. It’s challenging, to say the least. Because we’re farther north than the US, our areas of arable land are much more limited. Our growing season is shorter, and the range of crops that can be grown is more restricted. That also limited early settlement patterns.
Granted, but the US has several large settlements in otherwise useless territories that started as mining or oil towns. Nothing grows outside of Vegas, Houston, Phoenix, etc. but millions live there.
Bloody good answer that, blue infinity
Of about 200 countries in the UN, I believe only Mongolia has a lower average population density than Australia’s 7 per square mile. As with elsewhere around the globe, water holds the key to sustainable development, particularly initial settlement.
45% of continental Australia is desert. In terms of area that would the equivalent of the USA’s lower 48 being desert west of a line from Chicago to New Orleans.
Not in Australia anyway. There are more people living in the interior zones now than before white settlement. Primarily in mining towns.
Just like the more recent arrivals, indigenous locals preferred places where it rained reliably, even better with ocean views.
I’ll do it a little differently for Canada as the first regular national Canadian census was taken in 1871.
US population in 1871 … 38.5 million
Canada population in 1871 … 3.5 million
US population in 2013 … 316.5 million (8.2x the population in 1871)
Canada population in 2013 … 35.15 million (10x the population in 1871)
Why is the population of the US growing so slowly (compared to Canada)? Are there some historical or political reasons for this?
Yes, I know quite a few Canadians who visit Vegas or even winter in Phoenix- but nobody comes up to “summer in Yellowknife” or gamble in Halifax. The prairies are at the limit of habitation. Outside of agricultural area, native inhabitants were sparse and survived by hunting and fishing. Other than mining (or tar sands) there’s no real incentive to settle the northern areas.
In fact, I keep reading dire warnings that development is outpacing water supplies in areas like Phoenix and Vegas. The only city in Canada I can think of that exceeds its “agricultural carrying area” would be Vancouver which combines a transport stop like New York with a climate the envy of the rest of the country.
The Colorado River annually provides 16million acre feet of potable water to that region; predominantly from snowmelt off the Rockies.
It probably hasn’t snowed in central Australia since Gondwanaland broke up 65million years ago.
Your numbers don’t show this to be the case. Assuming an exponential growth model, you have a growth factor of 0.0497 per year for the US, and 0.0494 for Australia.
I always thought the Canadian west coast was kind of geography adding insult to injury. In eastern and central Canada, the limitation is simply one of latitude and the rapidly-deteriorating agricultural climate as you go north. On the west coast though, latitude isn’t a problem because ocean currents send warm water north, meaning the wet temperate Pacific Northwest climate that’s so great for agriculture in Washington, Oregon and Northern California extends essentially to Alaska. The only problem is that the big coastal valleys that are agricultural powerhouses in the PNW basically stop in Vancouver and the rest of the BC coast is almost all mountains. Thus, nature cheats Canada out of yet another potentially huge agricultural region!
I don’t think that’s true. My understanding is that the Native Australians lived mostly in the coastal areas until the Europeans arrived. They were then pushed into the more uninhabitable parts of the continent as Europeans took over the good parts.
White fellas also inhabited vast parts of the country that are now abandoned, the problem is the Australian climate is extremely variable, you start farming, do OK for a few decades then decades of drought. The Aboriginals inhabiting the arid fringes moved around to survive
Why does Alaska have so few people? It’s two and a half times the size of Texas but Texas has 35 times as many people.
Yes, yes, not all of Canada is like Alaska. But an almost unthinkably massive part of it is, and without the benefit of fishing ports to liven things up. And then there are all the other parts that, if you look at their rough equivalents in the USA, are not going to be jam-packed either. North Dakota (the Prairies), downeast Maine (the Maritimes), and northeastern Minnesota (the Canadian Shield) are not very densely populated either.
Actually, Canada seems to have done better at building cities on the northern Great Plains. Winnipeg, Calgary, Edmonton, Regina, and Saskatoon all seem to be bigger than anything on that end of the US side. We have, what, Bismarck?
I’ll grant you Phoenix and Vegas, but the land around Houston is well-watered and fertile. And Houston did not start as a mining town. That general area was where the first colony of Texians was located and they were farmers.
It doesn’t have to be rock just because it’s a continental shield. That rock could be covered with soil. The reason it’s not is the Pleistocene ice age.
After being covered by kilometers-thick ice for thousands of years, any land is going to barren with no topsoil. And Canada has been covered by 15 to 20 glaciations in the past 2 million years. The most recent glaciation ended about 10,000 years ago, which is not enough time for the soil to be rebuilt everywhere.
Northern areas in the US are also less fertile due to glaciation, but since the ice melted earlier in that region, it has had more time to recover. Also it’s closer to areas not glaciated. Some of the recovery has to do with how quickly the land can be recolonized by plants and soil-inhabiting animals such as worms. This also applies to southern Ontario, so it’s more fertile than the rest of the province. In Quebec, the only area that’s recovered is a fairly narrow strip along the St Lawrence River. Occasional flooding by the river will deposit mud, which contributes to soil recovery.
The western prairies were not covered by as much ice during the ice age. It is too dry in that region for thick glaciers to build up. Thus Saskatchewan, Alberta, and part of Manitoba are quite fertile compared to the rest of the country.
Closer to the truth is that those that lived in the coastal areas died out. Those that lived in the arid interior were isolated from the devastation, and persisted. The single biggest devastation was disease. Many parts of Oz were depopulated by a spreading wave of pestilence that preceded white settlers.
But for the OP. The interior of Oz is desperately barren. With rains that may simply fail to arise at all for a year or more. Or in the top end, flooding monsoons, and then dry.
It gets hot here, and hot across a lot of land.
And it doesn’t rain here all that much anyway. 50% of the land area gets less than 12 inches of rain a year. Average. Some years it gets nothing at all.
We have essentially one major river. It is in the east. Almost all of the continent has no useful rivers. You will see lots marked on the maps. They are dry. They run once every decade or so when the flooding rains come to push the average rainfall back up to 12 inches after 9 years of drought.
The area of land where it is desperate is big. The area of good soil is restricted to the coastal areas, and the band of land where you can reliably grow crops of any productivity less than 20% of the country. The areas where you get good crops is vastly smaller again.
Some image refs culled from here: http://www.fao.org/ag/agp/agpc/doc/counprof/australia/australia.htm