Its buildings "comprise an exceptional collection of fully realized and generally well-preserved Tudor Revival-style institutional architecture", which were designed by Cass Gilbert.

Being the first and only treatment center for tuberculosis in the country, its 45 beds quickly filled and the waiting list began to grow.

The State Tuberculosis Commission knew they had to expand but were unable to do so because the McCook family, who owned the neighboring property, refused to sell.

In 2014, Governor Dannel Malloy made a final decision to rebuild the Seaside Sanatorium as a state park.

[3] In 2023, the State of Connecticut authorized funding to remove the deteriorated buildings, protect the site from flooding and commemorate its historical significance, and make improvements for the public such as adding walking trails and bathrooms.

In July 2024, Connecticut’s Department of Energy and Environmental Protection (DEEP) solicited public input into the redesign of Seaside State Park.