From my POV, the Khan Academy view of history described here is utter bunk and doesn't really give a good historical perspective. I'm shocked, shocked to hear that K-12 history is garbage!
K-12 history curriculum has always been garbage pushing somebody's agenda.
Until the 80's, high school history in the US was all about the "American Pageant", complete with a carefully crafted timeline of achievement and wonderfulness describing how wonderful the US was. You start out making pilgrim hats in second grade and learning about how the friendly indians taught the pilgrims to put dead fish around corn as a fertilizer, and wrapped up talking about how great WW2 was. (Usually we ran out of time for Korea and Vietnam when I was in school)
From the 70's onward, "revisionists" changed the curriculum a bit to demonstrate that people other than white folks existed. For me, that meant in the winter you spent less time covering the gilded age and watched "Shaka Zulu" or "Roots" instead and in the Spring you learned about the civil rights movement. I grew up in New York City, so we were also mandated to learn about the potato famine and the triangle shirtwaist fire.
AP History was an eye-opener to me. You actually had an opportunity to leave the drivel behind and learn about something in depth from primary and secondary sources. (In my case, the American Revolution)