Major General Edward Braddock's Expedition of 1755 passed through the southwestern portion of the area that became Addison Township. The township was organized in 1800. Somerfield was laid out on the western edge of the township about 1816 by Philip D. Smyth, but the town was abandoned and covered over by the Youghiogheny River Lake in the 1940s. The Wable-Augustine Tavern was added to the National Register of Historic Places in 1995.