12. The Blockhouse/Central Park
The Blockhouse, located in the northern section of Central Park, was completed in 1814, two days before the treaty that ended the War of 1812 was signed. It was constructed on the remains of a Revolutionary War era fort.
Civil War Era
After the War of 1812, the United States began to buttress its harbor defense system. New York City, with its numerous waterways, greatly benefited from this construction boom.