My argument cannot be against selection, simplification, emphasis, which are inevitable for both cartographers and historians. But the mapmaker’s distortion is a technical necessity for a common purpose shared by all people who need maps. The historian’s distortion is more than technical, it is ideological; it is released into a world of contending interests, where any chosen emphasis supports (whether the historian means to or not) some kind of interest, whether economic or political or racial or national or sexual.

…

To emphasize the heroism of Columbus and his successors as navigators and discoverers, and to deemphasize their genocide, is not a technical necessity but an ideological choice. It serves—unwittingly—to justify what was done.

Howard Zinn — A People’s History of the United States, 3rd edition, pages 8 & 9.