Over the past several weeks, I've been immersed in historical research for an article I had to write. In reading and cross-referencing primary sources and maps dating back to the exploration of North America, I learned more about the early days of this country in those weeks than I did in all of my history classes combined.
I've also learned that much of what was taught in those classes was not only skewed, it was far from complete. Imagine looking at a single puzzle piece and developing an image of the overall picture along with the thoughts and motivations of the subject presented. That's what instructors ask us to do.
So ignore what your history teacher tells you--he or she has an agenda. Study historical events on your own using primary resources.