What defines history?

I've been wondering about this for a few days... ever since my principal showed me the new outline of what my superintendent expects to have us teach for American History next year.  Apparently my superintendent has decided that high schools will have a year of American History from 1950 to the present because "that's all he taught when he taught history."  First of all, I don't think that's a quantifiable reason to determine the curriculum change.  Secondly, how do you teach A YEAR of courses on only 60 years?  And finally, how can I be sure that the students understand everything that happened before 1950?  They are young and immature in high school, and our history is FILLED with things that need be delved into deeper than middle schoolers can do.  For example, the fear of Communism really started in America in about 1919.  In high school, I'd be starting the Cold War.  How am I suppose to get the to truly understand the fear that ran through the nation, if I'm suppose to start when that fear explodes?  Which means I'll be teaching the early things anyway, so they might as well let me keep American History from Post-Civil war on.  
I know it's not obvious, but I'm not a fan of my superintendent.  He's one of those guys who makes a decision and that's the end of discussion.  No taking anyone else into account.  I understand that this CAN be a good quality, depending on the situation, but when you're changing a curriculum, you should talk to someone who is a professional at writing curriculum AND talk to people who have specialized in that core area.  For example, there are plenty of teachers in this district who are continuing their education in history, AND are good educators.  Those are people who should be allowed to give feedback.  I feel that sometimes administration makes decisions and believes they're the correct decisions simply because they work in administration.  They feel that teachers should just be amazing at everything (which is what we are, so I understand that) but if we could have input, we'd at least be able to understand what and WHY we're teaching certain things.  I just feel that I am a better teacher if I understand the purpose and benefit to the kids. What is the purpose of only truly understand current history but NOT understanding how we got here?  Isn't it crucial for them to understand the mistakes of our forefathers so we can do better?  So we can be better?  I wish that some people in power would get rid of their arrogance and admit that they don't have all the answers.  It's a sign of strength to show you don't know everything, not a sign of weakness.  The weakness is being afraid to ask for help in making the best choice.


"It takes more courage to reveal insecurities than to hide them, more strength to relate to people than to dominate them, more 'manhood' to abide by thought-out principles rather than blind reflex.  Toughness is in the soul and spirit, not in muscles and an immature mind."  - Alex Karras