Horsham Township is named after the town of Horsham in Sussex County, England. Horsham is one of several townships in Montgomery County whose shape and size were determined by master survey lines drawn by William Penn's engineers as they first plotted this part of the colony for sale and settlement. Parallel lines, projected at intervals of a mile and a half and extending in a northwesterly direction from settlements along the Delaware, served not only as base lines for measurement of individual land grants but also as courses for future highways. County Line Road, Horsham Road, and Welsh Road are examples of highways so laid out. The effect of these survey lines upon the developmental pattern of Eastern Montgomery County is very much in evidence today.
In 1684, the entire township of 17 square miles was made available to individual purchasers. Samuel Carpenter, from the town of Horsham in Sussex County, England, after which the township is named, purchased five thousand acres, forty-two hundred of them within the present boundaries of the township. In 1709, Carpenter, then treasurer of Pennsylvania, began to sell tracts of land to migrating Quakers. In 1717, Horsham Township was established as a municipal entity by a vote of the people.
In 1718, Sir William Keith, then Lieutenant Governor of Pennsylvania, acquired twelve hundred acres of Carpenter's land on which he erected a house in keeping with the dignity of his office. The development of Keith's "plantation" proved to be a step in establishing closer ties between Horsham and neighboring communities, particularly those of Hatboro and Willow Grove. He was responsible for the construction of the present Easton Road (US Highway 611) from the Old York Road junction at Willow Grove to his mansion on County Line Road in 1722.
The first significant settlement in the township revolved around the junction of Horsham and Easton Roads and was known as Horshamville. Keith's extension of Easton Road prompted the establishment of the Horsham Friends Meeting House. The township's early social and economic life revolved around this Meeting House.
Through most of the early and mid 19th Century, Horsham's population grew slowly. Its character was not altered in any significant way until about 1872, when the North Pennsylvania Railroad extended a rail line from Glenside to New Hope and established a station in the nearby community of Hatboro, two and three quarter miles east of the nucleus of Horshamville. Horsham-Hatboro-Byberry Road provided easy access to Hatboro's station and, as a result, residential development began along the road virtually linking the two communities together. By 1890, the township's population reached 1,300.
In 1926, Harold F. Pitcairn, a pioneer in the development of the autogyro, a forerunner of the helicopter, outgrew his flying field in Bryn Athyn and purchased 191 acres of farmland along Easton Road in the vicinity of Graeme Park. The new "Pitcairn Field" remained in operation for testing "autogyros" until 1942 when the United States Navy purchased the field.
Montgomery County includes some 500 square miles and 635,000 plus residents. Yet, its population is diverse enough to include such residents as middle-income suburbanites, Pennsylvania Dutch farmers and affluent Main Liners. The eastern portion of the county is a densely populated, suburban area with large commercial and industrial districts throughout the region. Moving westward, the natural beauty of the land is allowed to open up until, in the far western section, a rich, productive farmland totally replaces the suburban districts.