This essay decodes a Wall-DNA in American culture with an examination of two shaping moments in history, namely the Founding Fathers and the Mexican-American War. It argues that the Trump Wall, instead of protecting, endangers American values and opportunities; instead of uniting the nation, divides it and ignites cultural wars. The Trump Wall portends fear, bigotry, distrust, intolerance and disconnection; it is the Trump War. Therefore, this border construction is more of a mental construct than a physical one, especially when it involves a cultural re-landscaping and boundary shifting between the US and Mexico and within the two nations. The essay also challenges a one-dimensional and static view on American values, and calls for a 21st century sophistication for a culturally nuanced definition of what America means, and a 21st century agility to cross back and forth any walls without sparking a war.