Fort Pulaski was built from 1829 to 1847 on Cockspur Island at the mouth of the Savannah River. It was named in 1833 for Casimir Pulaski, a Polish-born soldier who fought in the American Revolution. About 25 million bricks went into it, supported by wooden pilings sunk up to 70 feet.
As a young second lieutenant, Robert E. Lee worked on its construction under Major Samuel Babcock. Sources disagree on how thick the walls were, from about 7½ to 11 feet.
In April 1862, Union forces used 36 guns, including James rifled cannons and Parrott rifles, to breach the corner wall within about 30 hours. Colonel Charles H. Olmstead surrendered reluctantly. Only two soldiers were killed. The success of rifled cannon rendered brick forts obsolete. It became a national monument on October 15, 1924.