Southern Arizona wasn’t always part of the United States. After the Mexican-American War ended in 1848, the new border between the U.S. and Mexico followed the Gila River. That meant Tucson, Yuma, Nogales, Bisbee, Douglas and future Tombstone were all still on the Mexican side. Then the U.S. wanted a southern railroad route. So in 1854, it bought roughly 30,000 square miles from Mexico for $10 million in the Gadsden Purchase. That one deal helped create the Arizona map we know today, adding about a quarter of the state’s modern land area. But the new border also split Native homelands that had existed long before either country drew that line. The Tohono O’odham Nation still stretches across both sides of the modern border today. Arizona’s southern border didn’t always look like this. It was moved there. #ArizonaHistory #Arizona #Tucson #GadsdenPurchase #DownInnaDesert