The original portion of the large brick Renaissance Revival complex was designed by Gridley James Fox Bryant and was built in 1857, with a sympathetic enlargement c. 1915-20.

The original portion of the complex occupies the southeast corner of the block, the junction of Turner and Court Streets.

The main block housing the original courthouse occupies that spot, and is a rectangular structure oriented east-west, two stories in height, set on a basement that appears partially raised due to the sloping lot.

This section is topped by a steeply-pitched hip roof and an octagonal tower with cupola, and features the most elaborate styling.

The county commissioners sought to immediately solidify the decision, commissioning the design of this complex from Boston architect Gridley James Fox Bryant.