[1] The Army constructed Fort Gratiot in 1814 as an outpost to guard the juncture of the Saint Clair River and Lake Huron.

The Army then returned from 1828, and rebuilt the fort to a somewhat smaller size than the original,[4] also building some timber-framed structures on the site, including a hospital and officer's quarters.

[7] Pine Grove Park occupies part of the fort site.

The timber-framed hospital and officers quarters were moved multiple times within the fort, finally being placed in the western section, along what is now St. Claire Street.

In the 1980s, archaeological work determined the age of the structures, and in 2000–02, the Port Huron Museum acquired both homes and moved them to a lot in Lighthouse Park, where the Fort Gratiot Lighthouse is located.