Sept. 9-13 marks the anniversary of arguably this area’s most important historical event—and sadly, its least known one. The Texas Historical Commission refers to Lyman’s Wagon Train Battle as the beginning of “America’s most important war, which you know nothing about.” So, what’s the big deal, and why don’t we know anything about it? 146 years ago, this week: Sept. 9, 1874 On a very hot, dry…