Eschatology can be seen as necessary condition to any etiological or cosmogenic narrative - how and why did my world begin, how and why will it end?

Modern Apocalyptic literature is usually tied to Mary Shelley's The Last Man with H.G. Welles being the stand out author of the 19th Century. This is a helpful link about literary efforts pertaining to the future: http://www.brainpickings.org/index.php/2012/11/21/giorgia-lupi-future-timeline/

Many religious works include commentary on the future, with The Book of Revelations being the most famous, with tremendous amounts of commentary.

You could alternatively look at economists like Malthus as being a thoughtful piece on the future.

Or any of the speculations of scientists and engineers like Condorcet, Franklin, or the great russian rocket scientist [Tsiolkovsky].(http://en.wikipedia.org/wiki/Konstantin_Tsiolkovsky)

Or Armes Prydein, a welsh prophetic text.

Or in a similar vein Chen prophecy.

I am not sure what your focus is, but while you will have difficulty finding novels from before the 20th century, there is a tremendous wealth about information about the future.

This will be my last thread on reddit so I hope it will be of some help.