Hanover Township is, in a sense, the oldest township in Beaver County because that name was applied to the land when it was part of Washington County-before any of the other five original townships were named in Allegheny County. According to Bausman's History, "No township in Beaver County is richer in historical incident than Hanover." Originally a triangle extending from White's Mill on Raccoon Creek to the Virginia state line on the Ohio River, the township boundaries were changed in 1812, and Hanover became roughly rectangular in shape. Except for the incorporation of Frankfort Springs Borough in 1844, the boundaries remain unchanged. The Dungan family, recognized by Bausman as the first permanent settlers in Beaver County, made their home here in 1771 or 1772. Part of Levi Dungan's original farm is now the Ponderosa golf course.
Frankfort Springs, in the southern part of Hanover Township, was a popular health resort as early as 1800. In fact, Frankfort village nearby became Frankfort Springs Borough upon incorporation to retain identification with the busy recreational area several miles to the northeast (now in Raccoon Creek State Park). Comettsburg, in the southwest corner of the township, was an early village and post office, and it remains a center for a group of very old stone and brick homes. At Murdocksville, in the southeast, is the oldest landmark of significance in Beaver County: White's Mill, used to determine the boundary of Allegheny County when it was expanded in 1788 and of Beaver County when it was formed in 1800. Hanover village in the northeast is the site of an early Presbyterian church. Harshaville, an early post office, was associated with the village, but the name is also bestowed on the crossroads in the valley to the east.
High, rolling country, Hanover Township has remained primarily a farm community since it was formed although some oil was produced in the western part of the township. The twentieth century greatly reduced the number of farms in the township, but new uses were found for the land. A Citizen's Conservation Corps encampment was established on the headwaters of Traverse Creek during the depression. It is known today as the Linsly Outdoor Center. In 1948, some 8,000 acres, including this camp, were given to the state of Pennsylvania by the federal government. Today, Raccoon Creek State Park is one of the state's most intensively used recreational properties, and a Youth Forestry Camp is still maintained here by the state. Many fine homes have been built by families seeking to escape the residential congestion of Allegheny County to the east.