French Guiana belonging to Brazil continuously from 1809

Several months ago, when someone gave me a few suggestions about my British Argentina website, one of the suggestions was that an Argentina that becomes British in 1807 leads to a Brazil that doesn't give up French Guiana in 1817. To give a bit of background, in this universe just like in the one where Argentina became British, the Portuguese based in present-day Brazil invaded Cayenne (and French Guiana in general) in 1809 and occupied it for a number of years. I was thinking over and over and over about how exactly a British Argentina would lead to the Portuguese (and then Brazil) wanting to appease the British by having the Portuguese/Brazilians hold on to French Guiana for good. I figured eventually that the British and the Portuguese, in that other world, go to war on the frontier between Brazil and the British possessions to the south anyway, even though normally they've been allies from way back when. This, among other things, made me abandon the idea of linking the two, not to mention that among the Portuguese, there were some who wanted to annex French Guiana but many more who weren't interested in such an annexation.

Anyway, I'll briefly describe yet another real-life parallel universe, one in which Brazil keeps its hold on Cayenne and French Guiana - and where there are no historical changes anywhere else in South America. Firstly, in that case, the area is an additional Brazilian state known simply as Guiana, with the capital being Caiena. (The other French-sounding names get transformed into their Portuguese counterparts, too - e.g. Kourou becomes Curu.) The legal system there has some French elements left over from its pre-Brazilian days along with Portuguese law. Plus, there was no French-Brazilian dispute over Amapa (between Guiana and the Amazon Delta).

Another feature of that parallel universe is that the French didn't place any penal colonies near Caiena from the 1800s onwards (though they did in the late 1700s) like in this universe - Devil's Island comes most prominently to mind. Instead, New Caledonia (in the South Pacific northeast of Australia) saw an increase in French penal colony activity relative to our universe, so that the functions of Devil's Island took place in New Caledonia. Prisoners like Alfred Dreyfus (of the Dreyfus Affair from the late 19th century) were shipped to New Caledonia.

One other major difference between that universe and ours is that the French didn't relocate their main space centre to Curu (not far from Devil's Island and Caiena) in the 1960s after their withdrawal from Algeria (where the French had their previous space centre). After having considered many equatorial locations around the world, taking into account factors like political stability and the infrastructure as well as geography, the French decided to place the spaceport near Darwin, northern Australia. Just as the Guiana Space Centre became all of Europe's main spaceport in our universe, so too the Darwin Space Centre went on to be Europe's main space centre in the universe with the Brazilian-controlled Guiana.

There is also a slight difference in the distribution of country calling codes (exemplified by the United States and Canada having +1). In our universe, French Guiana has +594 as the country code. Take away that in the parallel universe under discussion, and we get Paraguay with +594 instead, along with Guadeloupe at +595, Suriname at +596, Uruguay at +597, the former Netherlands Antilles (except Aruba) at +598, Martinique at +599, and Aruba at +590. (Bolivia keeps +591, Guyana keeps +592, and Ecuador keeps +593.)