Some of the things that make the Berlin Wall and the Mexican-United States Border similar is that they are both actual walls, both had guards to keep people from crossing and both had people still cross despite of the guards. The things that make them different is that the Berlin Wall has been torn down, it was built to keep citizens in, and it only went across the city/state. In contrast, the Border Fence is still up, it was built to keep aliens out, and is built across the entire border between the U.S. and Mexico meaning 4 states and many cities.