Evans City is located in southwestern Butler County in the valley of Breakneck Creek. It is bordered to the north, west, and south by Jackson Township, and to the north, east, and south by Forward Township.
The site that is now Evans City was for a long time a favorite camping ground for Native Americans, who named the creek that ran through it Big Beaver Run, while the French knew it as Casse-cou-anse or "Breakneck Creek", a name adopted by travelers between Fort Duquesne and Fort Machault, and by the English-speaking pioneers of the original township of Connoquenessing. From 1804 to 1836, the location was often called "Boggs' Mill", and in later years "Evansburg", after Thomas B. Evans, who purchased and rebuilt the original Boggs' Mill.
In October 1878, the railroad was completed to Evans City; the first freight to be delivered was a new boiler to replace one which had exploded in the Sutton flouring mill. The burning question at the time was the location of the railroad depot. Once the location for the depot was chosen, it became a rather famous decision, creating the nation's only railway depot that was built over water. Spanning the Breakneck Creek on iron beams for support, the picturesque railway station was an iconic landmark of breathtaking architecture. Due to its age and growing structural instability, and against much popular protest, the station was finally demolished in the early 1980s rather than restored.
Later the school question occupied the attention of the people. Ultimately the schools were placed under the control of the Jackson Township board after a resolution by the Evans City school building committee was withdrawn.
In 1882 Evans City was incorporated as a borough.