In the spring of 1877 the Southern Pacific Railroad was building east on the first transcontinental line through Arizona. After getting permission from the federal government they spent the summer building a bridge across the Colorado River. Ironically, when they started to lay the track across the bridge another branch of the government wouldn’t allow them to cross a federal stream. At the time there were only five soldiers manning Fort Yuma, the commanding officer, Major Thomas Dunn, a doctor, a sergeant an enlisted man and a prisoner. With the exception of the prisoner, it was their duty to stop the railroad come hell or high water.
On the evening of September 29th, 1877, fearing the track layers might try surreptitiously to lay the tracks at night Major Dunn posted a guard on the bridge until eleven o’clock. The construction crew waited until the guard went off duty then they quietly began laying down track. Just before dawn a rail was accidentally dropped with a resounding noise and all four troopers rushed to the bridge with fixed bayonets. They stood bravely on the tracks but quickly realized they were no match for the approaching steam engine chuffing towards them. Deciding discretion was the better part of valor they jumped out of the way and let the engine pass. That morning the Southern Pacific Railroad rolled triumphantly into the town of Yuma.