[4] The original name of the town was Brookside, and subsequently Sunnyside in the 1890s,[5] but was changed for the railroad, by the time of its incorporation as a borough, due to an existing stop with the same name in Lancaster, Pennsylvania.

The borough's application for incorporation was granted in September 1896, and the office of burgess (later mayor) was established, to which James Douthett Magee was appointed, together with a seven-member council consisting of Edward Cowan, J. D. Perry, C. F. Harrobin, J.

[6] Valencia is located along the southern border of Butler County at 40°40′30″N 79°59′19″W / 40.67500°N 79.98861°W / 40.67500; -79.98861 (40.674906, -79.988493),[7] in the valley of Breakneck Creek near its source.

According to the United States Census Bureau, Valencia has a total area of 0.34 square miles (0.87 km2), all land.

The racial makeup of the borough was 98.18% White, 0.52% African American, 0.78% Pacific Islander, and 0.52% from two or more races.