Current teaching of History is improving from when we went to
  school. They're starting to show multiple competing perspectives
  which allows for discussion and critical thinking.

  I happen to take view #3. You happen to take view #1.

  Such is the nature of historical belief.

  [1]http://teachinghistory.org/issues.../research-brief/19265
  The first source below represents the popularity of the "flat
  earth"story in the 19th century. The second shows that knowledge
  of the round earth preceded Columbus and his voyage. And the
  third addresses one question generated by these two: Was there a
  great interruption in European geographic knowledge?

  1. Columbus was one of the comparatively few people who at that
  time believed the earth to be round. The general belief was that
  it was flat, and that if one should sail too far west on the
  ocean, he would come to the edge of the world, and fall off.
  (Eggleston, 1904, p.12)

  2. Scholars believe the sculpture, Atlas Farnese (above, left),
  was made sometime after 150 A.D. Named for the collection of
  which it is now a part, it was found in Rome in 1575. The
  globe's representation of the vernal equinox helped scholars
  date the sculpture.

  3. Dramatic to be sure, but entirely fictitious. There never was
  a period of "flat earth darkness" among scholars (regardless of
  how many uneducated people may have conceptualized our planet
  both then and now). Greek knowledge of sphericity never faded,
  and all major medieval scholars accepted the earth's roundness
  as an established fact of cosmology . . . Virtually all major
  medieval scholars affirmed the earth's roundness . . . (Gould,
  1995, p. 42) Of course. that's the point. But why promote
  progress in technology and science while hanging on to 19th
  century beliefs about history? That I'll never understand.
  Besides, Draper was a propagandist. He had an agenda, wasn't shy
  about it, made it very clear. He was also very successful at
  promoting it.

References

  Visible links
  1. http://teachinghistory.org/issues-and-research/research-brief/19265