A large factor in the advancement/financial disparity between the U.S./Canada and its neighbors to the south is the **difficulty of colonizing areas in tropical/subtropical climates vs. colonizing temperate areas**. The climates of these regions are vastly different. Very little of Earth's land lies in the temperate zone of the southern hemisphere.

(If I remember correctly this is somewhat covered in Jared Diamond's [Guns, Germs, and Steel][1], but of course anyone playing Civilization or a Paradox history game such as Europa Universalis knows you stay away from the jungle.)

(From [Reference.com][2]: "Areas with temperate climate enjoy weather conditions without large temperature extremes and with rainfall occurring throughout the year.")

Before modern medicine (and even today), **people living in warm or hot areas were more subject to disease** (such as malaria, which continues to kill hundreds of thousands of people each year in tropical climates throughout the world), with livestock and the crops that have generally sustained civilization more subject to disease as well. Additionally, **the grains and other crops such as wheat and potatoes that kept civilization going were grown in temperate climates** and were less likely to die off due to extreme variations in weather. 

For more on the crops that sustained settlers and where they were grown, see T.E.D.'s answer on another related question [here][3]. Note he refers to **indigenous peoples being removed from temperate areas for farming land** - one of the reasons you don't have large indigenous populations in temperate countries like the United States or Argentina, both of which received the largest influx of immigrants and both of which conquered and removed indigenous people. Note that Argentina has a larger GDP per capita than most Latin American countries, and has historically been somewhat more stable.

Combine this with the difficulty of taming the jungle vs. taming a temperate forest, and the ease of colonizing the United States vs. that of colonizing much of, for instance, Brazil becomes apparent.

**Please see a simple map of the areas in temperate zones vs. the areas in tropical zones below, followed by a more complex climate map.**

[![By KVDP - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=27385077][4]][4]

Below is the Koppel-Geiger map. T.E.D. posted a map similar to the one below, stating that **areas in green and tan are** good for growing crops. In the case of this map below, which is slightly different **dark purple isn't terrible**. Meanwhile, these areas are not as prone to disease.

[![enter image description here][10]][10]

**Compare these to pretty much any GPD per capita map**:

[![GDP per capita map][5]][5]

First of all, note that **the colonizing nations were all located in the temperate zone of the northern hemisphere, in areas that are green in the Koppen-Geiger map.** 

Secondly, note that **many of the states in the United States with the lowest income are in the subtropical areas of the country** (only Mississippi shows this on the GDP map, but it remains true for the much of the southeast). These states still have a high GDP per capita compared to the rest of the country. I currently live in Florida, which benefits from a robust tourist industry and isn't as bad off as where I'm from in Alabama, and I can tell you that not many people lived in Florida until the invention of air conditioning and modern medicine (and without either of those I wouldn't live here). There is little local history other than small settlements dotting the state. Note that even the hottest parts of Florida are above the Tropic of Cancer. 

For another example, see that tiny part of Australia that lies in the temperate zone, and the borders closest to it? See how the green areas are all in this zone? Compare it with this map of population density:

[![Australia population density][6]][6]

**Most Australians live in or near the edge of the temperate zone, in the green areas of the Koppel-Geiger map**, and even those people were dragged there from England, which was exactly in the middle of the temperate zone and is as dark green as you can get. One might also compare Australia and New Zealand and their places in or near the temperate zone and their higher GPD per capita than their neighbors to the north.

Now take a look at **Uruguay, Argentina, and Chile, all of which have a relatively high GDP per capita compared to the rest of Latin America. These are the only major parts of South America in or near the temperate zone, and are the only areas that are green or tan.** They are [relatively free of malaria risk][7], and their higher GDP per capita compared to other Latin American countries likely corresponds to their climate.

On a similar note, as I mentioned in the beginning of this post, Argentina's climate caused it to [receive a vast number of immigrants in comparison with the rest of the world][8], largely displacing its indigenous peoples. 

> The strength of the immigration and its contribution to the Argentine
> ethnography is evident by observing that Argentina became the second
> country in the world that received the most immigrants, with 6.6
> millions, second only to the United States with 27 millions, and ahead
> of countries such as Canada, Brazil, Australia, etc.

As Santiago wrote in a comment below, the area of Asia that lies in the temperate zone seems to be an anomaly on the GDP map, but it is important to note that this area is sometimes called the "[third pole of the world][9]" for a reason (this is the reason I updated with the Koppel-Geiger map). While this area of Asia is in the temperate zone, the actual climate is cold and arid. Meanwhile, other anomalies lie in the middle east; oil explains the discrepancy.

As for politics: **the politics of places that have a higher GPD per capita and less strife between indigenous peoples and immigrants are generally better over the long term**. 


  [1]: https://books.google.com/books/about/Guns_Germs_and_Steel_The_Fates_of_Human.html?id=PWnWRFEGoeUC&source=kp_cover&hl=en
  [2]: https://www.reference.com/science/temperate-climate-390b94c325f6d5bb
  [3]: http://history.stackexchange.com/a/21079/24322
  [4]: https://i.sstatic.net/wn8Zr.png
  [5]: https://i.sstatic.net/OD2u9.jpg
  [6]: https://i.sstatic.net/5qUGu.jpg
  [7]: http://www.netdoctor.co.uk/medicines/a5931/guidelines-for-malaria-prevention-in-central-and-south-america-and-the-caribbean/
  [8]: https://en.wikipedia.org/wiki/Indigenous_peoples_in_Argentina
  [9]: http://www.eos.unh.edu/Spheres_1110/wsc.shtml
  [10]: https://i.sstatic.net/5dOeo.png