Aragorn's Long Lifespan
 

I'm sure this question has been answered before, but what caused Aragorn to live much longer that other men?

He belongs to a race of men from Numenor, who all have longer than normal lifespans because they are descended from Elros, who was half-elven.

Yes, he was through long generations, but the life of the Numenoreans became shorter and shorter after they captured Sauron and especially after they turned against the Valar.
Yet the blood of ancient Numenor ran almost pure in Aragorn, and therefore he had a very long lifespan.

greetings,
lathspell

Aragorn is Isildurs heir who is from Numenor and they have a longer lifespan than normal men.