Depot Square sits at the confluence of the Contoocook River and Nubanusit Brook. The earliest town center in Peterborough was up on the hill, just across the Contoocook to the east. But soon the advantages of the river valley influenced the establishment of business and industry in the current downtown location.
The first buildings in what is now Depot Square were an odd assortment of sheds and workshops. In 1844 the school district purchased some of the land and built a large (three-room) schoolhouse, which sat approximately where New England Everyday Goods is today.
At that time, School Street was laid out, which provided easier access for other enterprises. The railroad came to town in 1861, and with it, the depot and Depot Street, connecting Main Street to School Street, was established.
The original depot was located approximately where the Toadstool Bookshop is today. The current building was constructed in 1961 and was originally an A&P grocery store.
The train tracks crossed the Nubanusit just at the edge of the Contoocook River. Today the remains of the supporting pillars can be seen from Depot Park.