Monaca has been known by many names. A part of the area on which the borough now stands, then called "Appetite," was patented to one Ephraim Blaine in 1787. In 1813, Francis Helveti (or Helvedi, Helvety), described as a Polish nobleman, bought the large "Appetite" tract and raised sheep on it, but his venture was unsuccessful. Harmonist George Rapp, one of Helveti's creditors, complained in 1815 "about the risk Helvety is taking with the sheep," and in 1821, the property was sold at Sheriff's sale to Rapp.
In 1822, a town of sorts began when Stephen Phillips and John Graham purchased the property and established their "extensive boat yards" there. Phillips and Graham built numerous steamboats, including the "William Penn," which carried the Harmonists from their Indiana home to Beaver County and their last home at Economy. Seceders from the Harmony Society led by Count DeLeon in 1834 purchased the townsite from the boatmen, intending to establish a community, which they called "New Philadelphia." The "New Philadelphia" experiment dissolved and Count Leon departed, but many of the German settlers Leon had led there remained. In 1840 they incorporated the "Borough of Phillipsburg" from the Moon Township site. The first burgess was Frederick Charles Speyerer, and the first council Edward Acker, Jacob Schaffer, Henry Jung, George Forstner, and Adam Schule
Dr. Edward Acker established a "Watercure Sanatorium" in Phillipsburg in 1848, and in 1856 when the borough's first post office was established, it took the name "Water Cure." In 1865 Reverend William G. Taylor bought the Sanatorium buildings for his Soldiers' Orphans Home. The Home according to one of the students consisted of a "dormitory, dining room, schoolhouse, bathhouse, woodshed, carpenter shop and a two-acre playground. " It burned in 1876.
In 1866, "Thief Hall" was established to provide "a Christian college for the education of the youth of the Lutheran Church in Western Pennsylvania." In 1870, Thiel College was incorporated, but the College moved to Greenville in 1871.
In 1876, Caldwell's ATLAS described Phillipsburg as possessing "a population of 600, four stores, two hotels, a German Lutheran Church, a Methodist Church, and the Chapel at the Soldiers' Orphan School. It would be one of the best sites for a manufacturing establishment of any kind, especially if the new railroad is finished through it to Pittsburgh." The following year, the Pittsburgh and Lake Erie Railroad was built through town and manufacturing blossomed according to the ATLAS's prediction. Phoenix Glass Company began operations in 1880 as a "chimney factory," and continues the manufacture of glassware to this day. Other industries followed.
In 1892, the Borough's name changed again, this time to Monaca, after the French and Indian War era Indian Monacatootha. The shortened version of the name was first used by the Pittsburgh and Lake Erie Railroad on a station at the east end of town. Citizens who hitherto had crossed the river only by ferry were able to cross the first bridge to Rochester built in 1895. In 1930, it was replaced by the present bridge. In 1932, Monaca annexed the hilltop areas of Moon Township which constitute the Fourth and Fifth Wards of the Borough. This area is today largely built up as a residential district, while the commercial and manufacturing interests remain largely "downtown," in the original three wards.
By 1852, the borough had a "public brick school house" for the education of its young. In 1965, Monaca's new high school was opened "on the hill" at Allen Avenue and Ella Streets; an addition has recently been constructed to house the junior high school as well.