Mount Pleasant borough is located at what was originally the junction of two Native American paths.

With the coming of Europeans, those two paths - now known as Pennsylvania Routes 31 (east/west) and 819 (north/south)- became key access roads to the western wilderness and more populated areas in the east.

The road pioneered by the Braddock expedition passed through the western end of the future town in 1755, opening the area to settlement.

One source states that at the time of the American Revolutionary War, there was a settlement of "not more than a half dozen houses.

[4] In 1797, Nathaniel Marshall sold land to Andrew McCready, who laid out the design of the town.

The invention of the Bessemer process of steelmaking in 1859, which required coke (fuel), had a dramatic impact on the region.

In addition, a branch line of the Pennsylvania Railroad connected the borough to Scottdale, and West Penn Railways (an interurban trolley) served Mount Pleasant from 1906 to 1952.

[11] According to the United States Census Bureau, the borough has a total area of 1.1 square miles (3.0 km2), all land.

A large proportion of the residents are of Polish descent, as evidenced by the Tadeusz Kościuszko Club.