The great Columbian Exposition was drawing to a close on October 28, 1893. The eyes of the world had been on Chicago, and the city was feeling proud. Then came the terrible news—Mayor Harrison had been killed by an assassin.

Carter Henry Harrison belonged to a distinguished family that had given the country two presidents. In 1855 he arrived at Chicago as a young lawyer. He was active in the Democratic Party and served two terms in Congress. In 1879 he was elected mayor of the city.

Harrison was a popular, accessible mayor. He often rode through the streets on a white horse, greeting his constituents. After serving four two-year terms, he retired. But when Chicago was chosen as the site for the Columbian world’s fair, he ran for mayor once again, and was elected to a fifth term in 1893.

On this evening, Harrison had returned to his Ashland Boulevard home after a long day at the fair, and was napping in a back bedroom. Around 8 p.m. a man named Eugene Prendergast appeared at the front door, asking to see the mayor. The maid thought she recognized Prendergast and let him in.

A few minutes afterward the servants heard loud voices, then three shots. They rushed toward the sound and found Harrison lying wounded on the floor. Prendergast was gone.

The mayor died within twenty minutes. A short time later, Prendergast turned himself in to police. He admitted the crime. His motive? Harrison had refused to appoint Prendergast as the city’s Corporation Counsel.

Chicago was plunged into grief. The closing ceremonies at the Columbian Exposition were converted into a memorial for the fallen mayor. Prendergast was quickly brought to trial, convicted of murder, and sentenced to death.

Prendergast’s brother appealed the sentence, saying that Eugene was insane. The attorney for the appeal was not-yet-famous Clarence Darrow. It was Darrow’s first murder case—and the only one he ever lost to the executioner. The appeal was denied, and Eugene Prendergast was hanged on July 13, 1894.

Four years after Harrison’s murder, his son—also named Carter Harrison—became mayor of Chicago. Like his father, the younger Harrison would be elected to the office five times.