Springfield township was once a part of the original Cool Spring township (the southeast quarter of the county), then in 1802 was in the region known as Wolf Creek township, and about 1805 a separate township called Springfield was created. This Springfield township as first formed contained the territory which in August, 1849, was set off as a new township with the name Findley.

The settlement of Springfield township began before the close of the eighteenth century. Robert Gilmer was a settler about 1797, and the Dennistons settled in the southwest part of the township a little later. Thomas McCoy came about the same time and married a Miss Denniston, and their descendants still live here.

Along the course later pursued by the Mercer-Butler turnpike were located at an early day the estates and homes of the Black family. Adam Black was the pioneer forefather of this family in Mercer county, and settled in Springfield township in 1805. Several members of this family were privates or officers in the war of 1812, and one or two were active in state politics. Of the present generation, several are well known in business and social life. The settlement near the north side of the township called Blacktown or Balm postoffice commemorated the family’s prominence in this locality. Henry Black built the first house here. The postoffice of Balm was established in May, 1858, the first postmaster being Joseph Bogardus, and was discontinued when the rural delivery system was inaugurated. Harriet Black was the first teacher of the school in the village, about 1847, and the first store was opened by a Black.

The Pittsburg pike, south of the bridge over Neshannock creek, passes by the original settlements of Springfield Falls and Leesburg. Leesburg in recent years has become a railroad station and the junction point of the Leesburg or Wolf Creek branch of the Pennsylvania Rail road. James Palmer built the first house in this locality, it is said, in 1828, and was one of the most active of that family in this township. A store in which were kept all the articles of merchandise needed by the people of the neighborhood was started by two Palmer brothers. About a mile north of the site of Leesburg, Arthur Johnson, who came in 1826, opened what was called the “New Lodge Inn,” and in December, 1836, when a postoffice was established for this vicinity it was opened in the tavern, with the landlord as postmaster, and was named New Lodge postoffice. This name it retained until 1845, when the change of name to Leesburg was probably coincident with the removal of the office into 

that village. The county system of rural delivery has resulted in the abandonment of the Leesburg office. The railroad station known as Leesburg is situated a mile or more west of the old settlement, and there is little to distinguish the roadside at Leesburg from any other rural landscape.

The Leesburg branch of the railroad, passing through the southern part of the township, has resulted in the development of the coal mines along this route, and the energy of some of the well-known citizens is directed to the operation of mines in this vicinity.

The village of London is located partly on land that was first owned by Adam Black. A postoffice was established there in March, 1848, David Gilson being the first postmaster. He also chose the name for the postoffice. 

Twentieth Century History of Mercer County, 1909, pages 157-158