Under contract to Historic Annapolis Foundation, Inc., URS Corporation conducted Phase II and III archaeological investigations of the 99 Main Street site (18AP21) in Annapolis, Maryland. The central building that stands on the site was constructed in 1791. The site is on Maryland's western shore coastal plain, on the Chesapeake Bay. Excavations were designed to mitigate adverse impacts to archaeological remains by the construction of the Annapolis History Center project.

A total of nine excavation units were excavated, and 42 features identified. Significant features included the remains of architectural foundations from early 18th century buildings that existed prior to the present structure. A collection of 6, 934 artifacts were recovered. Many of the artifacts and features date to the early 18th century, while a second concentration dates from the late 18th century. Historical documentation indicates the earliest remains are part of a bakery and dwelling compound known to be in operation by 1745. The lot was owned through much of the 18th century by Charles Carroll, and rented to various tenants. The bakery caught fire in January 1790, while under the operation of Richard Fleming, and burned down the entire city block. Archaeological evidence of the fire was abundant. Historical documentaion of the circumstances of Fleming's life, and records of similar fires in craft workshops in other cities at that time, suggest site 18AP21 was the scene of a class struggle between craftsmen and merchants for control of the emerging domestic economy in a new nation at the turn of the 19th century.

Areas of the site to be impacted by construction activities have been investigated and documented, through this work or through previous investigations. No further work is recommended at site 18AP21 at this time.