Behold, a 1854 Map of the world's tallest mountains and longest rivers (alt. link), as understood at that point in time, when Dhaulagiri was thought to be the tallest mountain in the world. This is taken from the General Atlas Of The World: Containing Upwards Of Seventy Maps, which can be read (awkwardly) on Archive.org as scanned from black and white microform, or go straight for the good stuff and browse the full color maps in David Rumsey's collection of high-resolution scans of historic maps (via Dark Roasted Blend and io9).
Northwestern University hosts a fine collection of historic East African photographs, viewable as sample sets or in their original photo-albums (requires flash). But the real prize is their wonderful collection of 113 historic maps of Africa, which are zoomable to incredible detail, also 1, 2, 3. via