One of the more infamous events in early San Bernardino history is known as the Ainsworth-Gentry Affair.

According to the “History of San Bernardino and Riverside Counties” by Johns Brown Sr., Alonzo Ainsworth and Thomas Gentry were both doctors in San Bernardino in 1859. There was a significant professional rivalry between the two. As if that were not enough, one was a Union sympathizer and the other was a son of the South.

The acrimony between the two finally boiled over and Gentry attacked Ainsworth one day with his horsewhip. Ainsworth managed to wrest the whip away and turned it back on Gentry, striking the other man in the face. The next day, when Gentry saw Ainsworth, he took a shot at the other doctor with his pistol. Ainsworth dodged the bullet and returned fire, but he also missed.

Gentry and his friends began making threats against Ainsworth. The friends of Ainsworth gathered around to protect him. Eight men armed themselves and took Ainsworth to an adobe house at E and Church Streets and kept guard over him for a few days.

In response, Gentry and his crowd sent word to El Monte, where Gentry had friends. They said they had been attacked by a gang of Mormons. About 50 -100 men from El Monte armed themselves and rode to San Bernardino.

Once the El Monte crowd arrived, it soon learned there was nothing to the claim. According to one account, upon learning the real story, “The better class of these visitors returned home.” Those from El Monte more inclined to lawlessness decided to stay and caused the little town of San Bernardino quite a bit of trouble.

Under the leadership of an unsavory character named Frank Green, the gang of desperadoes paraded through the streets firing guns and generally terrorizing the people of San Bernardino. The gang seized a cannon and took it to the house where Ainsworth was holed up.

The gang pointed the cannon at the house and announced its intentions to fire on the dwelling. However, someone managed to sneak up to the cannon and put a file in the fuse hole, rendering the weapon unusable.

Ainsworth’s friends had prepared for possible attack. They had left the adobe under cover of darkness and hidden in the surrounding corn fields. When the El Monte crowd realized that the men with Ainsworth planned to “save fire and shoot low” they quickly left the scene. Ultimately, some gun fire was exchanged, and one of Ainsworth’s friends, Bethel Coopwood, was injured.

The El Monte men were finally driven out of town when Sheriff V.J. Herring rallied the people of San Bernardino to help him restore order.

It’s not known what happened to the two doctors who started all the trouble.