Early advantages for the settlement were fertile soils and the limestone formations that were mined for the manufacture of mortar, plaster and whitewash.

[5] During the Civil War, the Reading and Columbia Railroad built a line through town, prompting a name change to "Union Station".

The tipping point was a major fire at the Denver House, a tavern built behind the train station in 1868.

Water from a local well and the nearby Cocalico Creek was insufficient to fight the fire, prompting tobacco merchant Aaron Shirk, physician W.D.

Fink and businessman Ephraim Renninger to press for incorporation, so a municipal water system could be created.

New industries sprouted up, including the F&M Hat Company, founded in 1912 by brothers Samuel and Daniel Fichthorn along with their brother-in-law Ambrose Marburger.

F&M Hat quickly grew into the town's largest employer, giving generations of residents jobs in its factory.

[5] In 1977, the Cocalico Eagles boys basketball team, under the direction of coach Ed McIlmoyle, defeated Mercer, 75–59, in the PIAA Class AA state championship game.

[7] Bucher's Mill Covered Bridge, south of Denver near Reamstown, was listed on the National Register of Historic Places in 1980.

Interstate 76, the Pennsylvania Turnpike, passes through the northern side of the borough, with the closest access 3 miles (5 km) to the east at Exit 286 (U.S. Route 222).