The Border Wall
USA Today...Interactive look at current US-Mexico wall along border
NatGeo...What the US-Mexico border actually looks like
Business Insider...29 photos that show the US-Mexico border's evolution over 100 years
Washington Post...Pancho Villa, prostitutes and spies: The US-Mexico border wall's wild origins
History...Everything you need to know about the Mexico - US border
SmithsonianMag...The raging controversy at the border began with this incident 100 years ago