The Frontier

Last year, I took HIST 361 - Western American History in the 20th Century - a very fascinating and interesting class!  On our first day of note-taking, we discussed Frederick Jackson Turner and others, & how thier spin on history have influenced us for over 100 years. 

There are several ways we can look at the Frontier: Little House on the Prairie, the Wild West, an almost fictitious era of America, as a topic of discussion and testing in school, Alaska, space, technology, still going on, etc.???

What exactly IS frontier?!