That too, but there's the geographical continuity which spans continents (at least as we generally classify them), cultures, language, and religion.

Resource curse isn't oil specific, and you might include some remote outliers into that group as well: Venezuela, Mexico, Brazil, and Nigeria, for example, all oil producers, and numerous others throughout the world based on other natural resources, with Nauru being perhaps the most spectacular boom-bust case.

The question of how / why / whether the US avoided the resource curse is another interesting one. I'd argue that it's similar to the case of the UK, in that 1) energy resources and industrialisation arose more-or-less simultaneously, 2) in a world with no industrial rivals and 3) with a fairly wide regional variance in both. In the case of the US, industry settled largely in the Great Lakes / North-East regions, whilst energy was focused in Texas, Oklahoma, and Louisiana. The latter three far more resemble resource-cursed countries in their economic, political, and socioeconomic profiles, though much of that is tied up in ... other historical baggage, to avoid taking this thread entirely off the rails ;-)