I have passed by this place many times as I traveled along Route 15 but never knew it was there until I scanned these slides. Amity Hall is/was just northwest of the confluence of the Juniata and Susquehanna rivers. It appears as Aqueduct in this 1907 topo map. You can see the dashed blue line of the old canal and where it crossed the Juniata on the aqueduct, hence the name.
A 1940s guide to the state says this; In Amity Hall, the State’s east-west and north-south canal systems intersected here, and the area is littered with canal remains. A short distance northwest of the junction are the stone piers of the old Pennsylvania Canal Aqueduct, which carried the Susquehanna Canal across the Juniata. The wooden trough of the aqueduct has long rotted away. Near by is a well-preserved lock.
I tried looking up the origin of the name Amity Hall and found this video of an old tavern/inn. The 1940s history says; The Amity Hall Inn (open May-Oct), built about 1810, is a two-and-a-half-story, red brick building, with gabled roof and dormer windows; the inn is furnished with many old household articles and old prints. A dormitory and lunch room here is much patronized by freight truck drives, and it is not uncommon to see from 50 to 100 trucks parked here at one time.
These slides were all dated April 1969. I don’t know if Earl took them or traded for them. You will see later that he did have a interest with the bridge at Clark’s Ferry, so I like to think that he might have been visiting and took these himself.
From Google Maps it looks like the lock and piers are still intact. Today the area is marked by the Amity Hall public boat launch.