Known before there was a RR depot nearby as Merion Square, the settlement's name was likely changed to Gladwyne by the Reading Railroad to avoid confusion with other stops with "Merion" in their names.
The Village of Gladwyne was listed onto the National Register of Historic Places in 1980.
In William Buck's book History of Montgomery County Pennsylvania, (Philadelphia: Everts & Peck, 1884) the following reference appears:
"Merion Square is located nearly in the centre of the township, at the intersection of several roads, and contains about thirty-five houses, two stores, two churches, school-house, several mechanic shops, and according to the census of 1880, two hundred and seven inhabitants. The post-office is called Lower Merion. The Methodist Episcopal Church was built before 1858, of which the Rev. A. W. Prettyman is the present pastor. The Presbyterian Church was built in 1877; is in charge of Rev. A. W. Long. Both have services twice every Sabbath and Sunday schools attached. The Odd-Fellows' Hall is occupied by Merion Lodge, No. 210, of I. O. O. F., and Montgomery Encampment, No. 115. Merion Square Division, No. 128, S. of T., also meet in the latter building. This village in 1858 contained twenty-six dwellings."
The following is from Montgomery County: The Second Hundred Years, Jean B. Toll and Michael J Schwager, eds., Montgomery County Federation of Historical Societies; Norristown, 1983
Gladwyne is still a quiet, walkable country village. Its center at the intersection of Youngs Ford and Righters Mill roads, historically known as Merion Square, includes small shops and single or double houses. The double houses, now privately owned, were once tenant housing for the laborers or mill workers of Mill Creek Valley. The name Gladwyne was adopted June 5, 1890, replacing Lower Merion, the official post office name, to avoid confusion with other "Merions."
Although Gladwyne is geographically undefined, the postal zoning map boundaries run from Mill Creek Road at the Schuylkill River along the west bank of the river to the borders of West Conshohocken, Villanova, Bryn Mawr, and Haverford.
Mill Creek flows through Gladwyne; all but one of its many mills have vanished or are in ruins. The earliest gristmill, begun by 1690, was followed in the eighteenth century by saw, paper, powder, and oil mills and in the nineteenth century by cotton, woolen, lamp wicks, buttons, and gun-parts manufactories. In mid-May 1894 a devastating flood wiped out many of the mills and destroyed all of the bridges. Losses totaled $100,000. A few mills continued on into the twentieth century, but the milling industry along Mill Creek was virtually ended.
School District: Lower Merion