Jackson Township was established in 1854 from portions of Cranberry and Connoquenessing Townships. There had been thirteen townships prior to that time. During 1853 and 1854, Cyrus E. Anderson presided over a group to assist people in recognizing the need for new townships in Butler County. A petition to create ten new townships each 5 miles square was submitted. Opposed to this action were three existing townships: Buffalo; Middlesex; and Cranberry. These townships asked that the petition to create new Townships be set aside. However, their request was denied. What resulted was a general sub-division of Butler County that established a total of thirty-three (33) townships. All but three of these townships were nearly 24 square miles in area. Jackson was one of the newly created townships. It was named for President Andrew Jackson who had served two terms as President of the United States from his election in 1828 through 1836.

In the early 1920's, work camps housed men who rebuilt and paved Rt. 68 between Zelienople and Evans City. Jackson funded the Rt. 68 paving through a bond issue. Route 19 was paved from the Harmony bridge to Scott Ridge Road in 1925. Until then, Mercer Road was dirt. In 1936, Rt. 19 was rebuilt, bypassing Harmony when a bridge was built over the Connoquenessing at Zelienople. Many roads were named for early families that lived on or near them. Roads have also been named for the town or towns the roads connect. Some are named for schools, which were once named for the family that created them. In the mid-1800's, the road from Cranberry to Zelienople was made of planks. However, money was scarce and the road was not properly cared for. It rotted and fell apart. Tollgate Road, which intersects Rt. 19 and Old Perry Highway, is a reminder of the plank roads. In 1857, those who did not pay the toll would be chased. Route 19 (Perry Highway) was the path for troops who hauled supplies for Commodore Perry's fleet at Erie in 1812. Franklin Road follows the Vanango Path from Pittsburgh to Erie via Venango, now Franklin. Logstown Path brought George Washington through Zelienople and Harmony on his way to Fort Le Boeuf near Erie in 1753.  After Basse bought 10,000 acres in 1802, he had a few roads cut through the wilderness and had a castle built on a hill overlooking Zelienople. Later George Rapp bought half of the Basse land. The Harmonites built the settlements of Ramsthal (Ramsdale) and Edenau in Jackson. Edenau became known as Harmony Junction when the trolley came.  There was a power plant along Rt. 68 near where Berry Metals is. The electricity was used for the trolleys. Coal from nearby hills was hauled to the surface by mule teams to fire up the plant.